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1.
Summary Bulbs and aerial parts of the Nepalese plant Allium wallichii are widely used for medicinal purposes and as a spice. Due to overharvesting the natural populations of the species have been increasingly reduced and the domestication of the species should be considered. For the purpose of the production of plantlets suitable for field culture, a micropropagation procedure based on multiple shoot culture has been established. Multiplication factors of 4.6 on average were possible on MS medium supplemented with 20 μM zeatin. After rooting on MS medium with 10 μM indolebutyric acid, plantlets were acclimatized to greenhouse conditions and transferred to the field with good success. Part of the PhD thesis of P. R. Malla.  相似文献   

2.
Peroxiredoxin systems in plants were demonstrated involved in crucial roles related to reactive oxygenated species (ROS) metabolism and the linked cell signalling to ROS. Peroxiredoxins function as peroxidasic systems that combine at least a reactivating reductant agent like thioredoxins, and sometimes glutaredoxins and glutathion. In the past three years a number of peroxiredoxin structures were solved by crystallography in different experimental crystallisation conditions. The structures have revealed a significant propensity of peroxiredoxins for oligomerism that was confirmed by biophysical studies in solution using NMR and other methods as analytical ultra-centrifugation. These studies showed that quaternary structures of peroxiredoxins involve specific protein–protein interaction interfaces that rely upon the peroxiredoxin types and/or their redox conditions. The protein–protein interactions with the reactivating redoxins essentially lead to transient unstable complexes. We review herein the different protein–protein interactions characterized or deduced from those reports.VNM is recipient of a PhD fellowship of the French Ministère de l’Enseignement Supérieur de la Recherche et des Nouvelles Technologies for the year 2003–2006 and the Research Doctorate School of Chemistry of Lyon.  相似文献   

3.
A delay in PhD completion, while likely undesirable for PhD candidates, can also be detrimental to universities if and when PhD delay leads to attrition/termination. Termination of the PhD trajectory can lead to individual stress, a loss of valuable time and resources invested in the candidate and can also mean a loss of competitive advantage. Using data from two studies of doctoral candidates in the Netherlands, we take a closer look at PhD duration and delay in doctoral completion. Specifically, we address the question: Is it possible to predict which PhD candidates will experience delays in the completion of their doctorate degree? If so, it might be possible to take steps to shorten or even prevent delay, thereby helping to enhance university competitiveness. Moreover, we discuss practical do''s and don''ts for universities and graduate schools to minimize delays.  相似文献   

4.
The perspectives and enthusiasms recorded in this review describe the events I witnessed and, in small ways, contributed to. Two great rewards emerged from my experiences – the pleasure of doing experiments and the great wealth of friendships with students and colleagues. As a graduate student, phenomena appeared at the bench before me which clarified the coupling of electron transport to ATP synthesis. My first PhD graduate student measured concentrations of pyridine nucleotides in chloroplasts and his results have been often confirmed and well used. All of the many graduate students who followed contributed to our understanding of photosynthesis. I have taken much pleasure from documenting the details of photosynthetic phosphorylation and electron transport in cyanobacteria. Studies of the `c' type cytochromes in these organisms continue to fascinate me. My experiences in government in its efforts to promote research are unusual, perhaps unique. A rare event outside the laboratory – a natural bloom of cyanobacteria – stimulated new thoughts and special opportunities for laboratory science. Photosynthesis seems magisterial in its shaping of our planet and its biology and in the details of its cleverness that were revealed in the time of my witness. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

5.
One of the challenges still open to wildland fire simulators is the capacity of working under real-time constrains with the aim of providing fire spread predictions that could be useful in fire mitigation interventions. We propose going one step beyond the classical wildland fire prediction by linking evolutionary optimization strategies to the traditional scheme with the aim of emulating an “ideal” fire propagation model as much as possible. In order to accelerate the fire prediction, this enhanced prediction scheme has been developed in a fashion on a Linux cluster using MPI. Furthermore, a sensitivity analysis has been carried out to determine the input parameters that we can fix to their typical values in order to reduce the search-space involved in the optimization process and, therefore, accelerates the whole prediction strategy. Baker Abdalhaq received the BSc. Computer Science from Princess Sumaya University College, Royal JordanianSocieaty, Amman Jordania in 1993. In 2001 and 2004, he got the MSc and PhD in Computer Science from Universitat Autónoma de Barcelona (UAB), respectively. His main research interest is focused on parallel fire simulation and, in particular, how to take advantage of the computational power provided for massively distributed systems to enhance wildland fire prediction. Ana Cortés received both her first degree and her PhD in Computer Science from the Universitat Autonoma de Barcelona (UAB), Spain, in 1990 and 2000, respectively. She is currently assistant professor of Computer Science at the UAB, where she is a member of the Computer Architecture and Operating Systems Group at the Computer Science Department. Her current research interests concern software support for parallel and distributed computing including algorithms and software tools for the load-balancing of parallel programs. She has also been working on enhancing wildland fire prediction by exploiting parallel/distributed systems. Tomàs Margalef got a BS degree in physics in 1988 from Universitat Autónoma de Barcelona (UAB). In 1990 he obtained the MSc in Computer Science and in 1993 the PhD in Computer Science from UAB. Since 1988 he has been working in several aspects related to parallel and distributed computing. Currently, his research interests focuses on development of high performance applications, automatic performance analysis and dynamic performance tuning. Since 1997 he has been working on exploiting parallel/distributed processing to accelerate and improve the prediction of forest fire propagation. He is an ACM member. Germán Bianchini received the BSc. Computer Science from Universidad Nacional Del Comahue, Argentina, in 2002. In 2004 and 2006, he got the MSc and PhD in Computer Science from Universitat Autónoma de Barcelona (UAB), respectively. His main research interest is focused on parallel fire simulation and, in particular, how to take advantage of the computational power provided for massively distributed systems to enhance wildland fire prediction. Emilio Luque received the Licenciate in physics and PhD degrees from the University Complutense of Madrid (UCM) in 1968 and 1973 respectively. Between 1973 and 1976 he was an associate professor at the UCM. Since 1976 he is a professor of “Computer Architecture and Technology” at the University Autonoma of Barcelona (UAB), where he is leading the Computer Architecture and Operating System (CAOS) Group at the Computer Science Department. Professor Luque has been the Computer Science Department chairman for more than 10 years. He has been invited lecturer/researcher in Universities of USA, Argentina, Brazil, Poland, Ireland, Cuba, Italy, Germany and PR of China. He has published more than 35 papers in technical journals and more than 100 papers at international conferences and his current/major research areas are: computer architecture, interconnection networks, task scheduling in parallel systems, parallel and distributed simulation environments, environment and programming tools for automatic performance tuning in parallel systems, cluster and Grid computing, parallel computing for environmental applications (forest fire simulation, forest monitoring) and distributed video on demand (VoD) systems.  相似文献   

6.
The canonical Wnt pathway contributes to the regulation of neuronal survival and homeostasis in the CNS. Recent evidence suggests that an increased expression of Dickkopf-1 (Dkk-1), a secreted protein that negatively modulates the canonical Wnt pathway, is causally related to processes of neurodegeneration in a number of CNS disorders, including Alzheimer’s disease (AD), brain ischemia and temporal lobe epilepsy (TLE). Dkk-1 induction precedes neuronal death in cellular and animal models of excitotoxicity, β-amyloid toxicity, transient global ischemia, and kainate-induced epilepsy. In addition, Dkk-1, which is barely visible in the healthy brain, is strongly induced in brain tissue from AD patients or from patients with TLE associated with hippocampal sclerosis. These data raise the attractive possibility that Dkk-1 antagonists or neutralizing antibodies behave as neuroprotective agents by rescuing the activity of the canonical Wnt pathway. Special issue article in honor of Anna Maria Giuffrida-Stella. Agata Copani and Ferdinando Nicoletti—Co-senior authors. Filippo Caraci—PhD Program in Neuropharmacology.  相似文献   

7.
The term “hypnozoite” is derived from the Greek words hypnos (sleep) and zoon (animal). Hypnozoites are dormant forms in the life cycles of certain parasitic protozoa that belong to the Phylum Apicomplexa (Sporozoa) and are best known for their probable association with latency and relapse in human malarial infections caused by Plasmodium ovale and P. vivax. Consequently, the hypnozoite is of great biological and medical significance. This, in turn, makes the origin of the name “hypnozoite” a subject of interest. Some “missing” history that is now placed on record (including a letter written by P. C. C. Garnham, FRS) shows that Miles B. Markus coined the term “hypnozoite”. While a PhD student at Imperial College London, he carried out research that led to the identification of an apparently dormant form of Cystoisospora (synonym: Isospora). In 1976, he speculated: “If sporozoites of Isospora can behave in this fashion, then those of related Sporozoa, like malaria parasites, may have the ability to survive in the tissues in a similar way.” He adopted the term “hypnozoite” for malaria in 1978 when he wrote in a little-known journal that this name would “… describe any dormant sporozoites or dormant, sporozoite-like stages in the life cycles of Plasmodium or other Haemosporina.” At that time, the existence of a hypnozoite form in the life cycle of Plasmodium was still a hypothetical notion. In 1980, however, Wojciech A. Krotoski published (together with several co-workers) details concerning his actual discovery of malarial hypnozoites, an event of considerable importance.  相似文献   

8.
The importance of diversity is self-evident in medicine and medical research. Not only does diversity result in more impactful scientific work, but diverse teams of researchers and clinicians are necessary to address health disparities and improve the health of underserved communities. MD/PhD programs serve an important role in training physician-scientists, so it is critical to ensure that MD/PhD students represent diverse backgrounds and experiences. Groups who are underrepresented in medicine and the biomedical sciences include individuals from certain racial and ethnic backgrounds, individuals with disabilities, individuals from disadvantaged backgrounds, and women. However, underrepresented students are routinely discouraged from applying to MD/PhD programs due to a range of factors. These factors include the significant cost of applying, which can be prohibitive for many students, the paucity of diverse mentors who share common experiences, as well as applicants’ perceptions that there is inadequate support and inclusion from within MD/PhD programs. By providing advice to students who are underrepresented in medicine and describing steps programs can take to recruit and support minority applicants, we hope to encourage more students to consider the MD/PhD career path that will yield a more productive and equitable scientific and medical community.  相似文献   

9.
Kim MH  Kim BT  Min YK  Kim SH 《Amino acids》2008,34(3):497-506
Summary. Cell-based signal chemical genomics can profile the signalling pathway for certain cellular events by using a target-known chemical library. To ascertain its usefulness, the receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in mouse monocyte/macrophage cells RAW264.7 was used as an in vitro experimental model. Of 180 target-known inhibitors/activators formatted in a 384-well plate, 8 chemicals were shown to inhibit the osteoclast formation, but 4 chemicals enhanced this process. A variety of references support, or possibly lead one to expect the effects of these 12 chemicals on the cellular process of osteoclastogenesis in RAW264.7 cells, but several signalling pathways were newly found in this study; for example, CA-074 Me inhibiting cathepsin B and nitrendipine blocking the calcium channel could have the potential to inhibit the osteoclast formation as well as bone resorption. This is a simple but very fast and powerful method of profiling the signalling pathway of certain cellular events. Signal chemical genomics could provide invaluable information for the exploration of new target signalling processes and further target-based drug discovery strategies. Authors’ address: Seong Hwan Kim, PhD, Laboratory of Chemical Genomics, Bio-Organic Science Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong-gu, Daejeon 305-600, Korea  相似文献   

10.
Since the 1950s, the number of doctorate recipients has risen dramatically in the United States. In this paper, we investigate whether the longevity of doctorate recipients’ publication careers has changed. This is achieved by matching 1951–2010 doctorate recipients with rare names in astrophysics, chemistry, economics, genetics and psychology in the dissertation database ProQuest to their publications in the publication database Web of Science. Our study shows that pre-PhD publication careers have changed: the median year of first publication has shifted from after the PhD to several years before PhD in most of the studied fields. In contrast, post-PhD publication career spans have not changed much in most fields. The share of doctorate recipients who have published for more than twenty years has remained stable over time; the shares of doctorate recipients publishing for shorter periods also remained almost unchanged. Thus, though there have been changes in pre-PhD publication careers, post-PhD career spans remained quite stable.  相似文献   

11.
For the 26th time in a row the Interuniversity Cardiology Institute of the Netherlands (ICIN-Netherlands Heart Institute) and the Netherlands Society of Cardiology (NVVC) have supported the competition for the best three cardiovascular PhD theses, published in the year 2014 [1–3]. The dissertation prize carries the name of one of the greatest Dutchmen in the history of cardiovascular medicine, Willem Einthoven, who in 1902 for the first time recorded the human ECG, for which he received the Nobel Prize in 1924 [4].This time the jury received a total of 28 PhD dissertations published in 2014. The jury members were very much impressed by the high scientific quality of the PhD fellows. The ultimate selection was based on a combination of several parameters: the curriculum vitae of the candidate, the scientific originality of the PhD thesis and its relevance for the cardiovascular field. In addition, several objective bibliometric parameters were used: (1) the number of articles in first-rate journals both in PubMed and the Web of Science (WOS), (2) the number of citations in WOS, (3) the Hirsch index and (4) the contribution as a first author (or shared first author).Based on a combination of these results, the jury finally selected three nominees: K.Y. van Spaendonck-Zwarts (University Medical Centre Groningen), N.M. van Mieghem (Erasmus Medical Centre, Rotterdam) and W.J. Dewilde (Sint Antonius Hospital, Nieuwegein).The members of the jury were: J.W. Deckers (Director CVOI), S. Heymans (ICIN professor), A. Mosterd (Chairman WCN), M.J. Schalij (Chairman Concilium NVVC) and V.A. Umans (President NVVC).The three candidates presented their Ph.D. theses at the annual spring meeting of the NVVC, held at the Congress Centre “De Leeuwenhorst” in Noordwijkerhout, 9–10 April 2015. Based on the quality of the presentation, the audience determined the ranking of the laureates. Mrs. dr. K.Y. van Speandonck-Zwarts received the third prize, dr. N.M. van Mieghem the second prize, and dr. W.J. Dewilde the first prize. We like to congratulate the three winners with their excellent PhD Theses. Summaries of the three nominated PhD theses are given below.  相似文献   

12.
A PhD thesis is a project with an established goal and a deadline. As such, the tools, strategies and insight of professional project management can be used effectively to improve both research success and personal well-being.A project is a “temporary endeavour undertaken to create a unique product, service or result” [1]. Although this is a generic definition, it pretty much describes any PhD research project. There are many ways to manage a project effectively and efficiently. Unfortunately, most of us are so busy with our science that we forget about the importance of planning and management to our own success, sanity and health. Instead, we approach our first three years of genuine scientific endeavour wide-eyed and unprepared to juggle the hundreds of tiny balls that make up a PhD. Several techniques from the realm of ‘project management'' might therefore be helpful for PhD students who need to plan and manage the many competing demands that doctoral research can place on them.A PhD comprises both the research itself and the acquisition of skills and knowledge that will facilitate your future career. As such, it is of paramount importance to establish your own objectives early on. For example, alongside dividing your project into work packages—smaller projects that might be discrete or might build on each other—it is also essential to define which so-called transferable skills—additional knowledge and experience that might improve your job prospects—you feel will be of greatest use to you, depending on what you want to do after your PhD. The importance of these skills is becoming more widely recognized and taken far more seriously, and you should find that your supervisor is willing to give you the time to pursue them—your institute or university usually requires that he or she does so. More importantly, you should give yourself the time to invest in these skills, as they are going to be vital to everything you do once your PhD project is over.Doctoral research requires a multitude of skills, most of which you will inevitably lack when you commence your PhD programme. The first step is to identify the gaps in your knowledge to plan what skills on which to focus. This will allow you to acquire them in good time, either through professional activities—shadowing a postdoc, teaching undergraduates, joining journal clubs and blogging—or through both internal and external courses and workshops to improve communication, presentation, writing, networking and other skills. In addition to your planned skills acquisitions, you will also have situations arise, in which you need to acquire new skills quickly. The more you plan training activities and skills acquisition in advance, however, the smoother this aspect will be of your PhD. By way of example, part of my own PhD project relates to statistical analysis of data. An early analysis highlighted several areas in which I had to improve my skills, including hierarchical cluster analysis, principal component analysis and χ2 testing against standard distributions. Having identified these gaps in knowledge early on in my doctoral programme, I could plan ahead accordingly when and how to acquire these skills.The full scope of your PhD project is usually unknown at the outset, and even the direction of your research might well change before you are finished. ‘Rolling wave planning'' is a technique that allows you to take these facts into account and plan the short-term future in detail, with a high-level provision for medium- to long-term activities. For those new to developing project schedules, I advocate a simple five-step approach. First, make an ordered list of high-level activities needed to achieve your goal. Second, expand this list by adding lower-level activities for which you have a detailed understanding of the scope, for example work to be performed in the next six months. You now have a work breakdown structure. Third, turn this work breakdown structure into a dependency-driven list by adding associations between the activities, for example by adding links to precursor activities that need to be completed before another activity can be started. Fourth, estimate the duration of each activity and extrapolate the start and end dates beginning with the first scheduled activity. Finally, as you progress through your research, and the scope of future activities becomes clearer, update the project schedule with these low-level activities as they become known. This approach of generating a hybrid-level project schedule, and updating with detailed activities as the scope becomes clearer, is known as ‘rolling wave planning''.…we approach our first three years of genuine scientific endeavour wide-eyed and unprepared to juggle the hundreds of tiny balls that make up a PhDThere is a range of professional software to help develop project schedules, but there are also various freeware tools available. Alternatively, you can use one of the many word processing or spreadsheet applications to make a simple Gantt chart. Along with the technical scope of your doctoral research, it would also be useful to include milestones that your institution enforces; for example literature review submission, formal progress reports and thesis chapter outlines. Including these in your rolling wave planning will allow you to keep in mind the bigger picture and the formal aspects that must be completed for your PhD, in parallel with the progress you are making towards your specific research subject.It is of course a cliché, but it is true that ‘failing to plan is planning to fail''. Of course the fluid nature of research makes it difficult to estimate accurately the time that it will take to complete various experiments, especially as a novice researcher. I therefore believe that although experiments do overrun and PhD projects can change, developing a project schedule is not a futile activity. By having a plan, even if it is made up of ‘guesstimates'', you can forecast roughly how much time you have left for your research and roughly what you can realistically hope to achieve. After all, without a plan, how can you predict when you will complete your research, submit your thesis and ultimately gain your PhD?Doctoral research requires a multitude of skills, most of which you will inevitably lack when you commence your PhD programmeThe serious consideration of scope is necessary in any project, but even more when you are simultaneously project manager, research scientist and key stakeholder. This raises various crucial questions regarding scope management: what is my doctoral research all about (the goal), and what work do I need to do to meet this goal? Once this has been agreed between you and your supervisor(s), it is essential to manage the scope of your project—the breadth and number of experiments you will perform—and how this will achieve your goal(s). Furthermore, be specific—knowing exactly what you want to achieve will keep you motivated until you get there.Project managers often use the concept of the triple constraint to manage work: scope, time and cost are intricately linked in a project and the different level of focus that each is given affects the perceived quality (by others) of project deliverables (Fig 1). Project managers understand that any deviation in one of the triple constraints changes one or both of the others. This is where the project schedule really comes into its own by allowing you to forecast when you will complete the agreed goals of your PhD project. For example, is your doctoral programme for a fixed-term period? If so, then once a project schedule has been agreed that uses all of the time available, any project overruns will cause an overrun to the overall PhD. The two main possibilities for a PhD student to manage this situation and bring the projected completion back into acceptable timescales are either to work longer or to reduce the scope or goals of the project, either by conducting fewer experiments to answer the same question or by modifying the depth of the question being asked. This leads to the issue of whether there is a minimum set of goals that need to be achieved, or whether several agreed activities are ‘nice to haves'', but are not crucial for the overall PhD. I believe that your supervisor(s) are best suited to answer questions about the minimum goals and the scope needed to achieve them.Open in a separate windowFigure 1The project management triangle as applied to a PhD. Three competing constraints influence project management: time, scope and cost. The time constraint reinforces that projects are temporary endeavours, and that in most cases have defined timescales (absolute deadlines). The cost constraint refers to the budgeted amount allocated to the project that, from the perspective of doctoral research students, will predominantly be focused on the amount and duration of the stipend awarded, but might also incorporate various expenses such as bench fees, conference fees and consumables. For those changing career, the cost might also comprise an element of salary sacrifice. The scope constraint refers to what must be done, produced or developed to meet the objective of the project, which in the case of a PhD generally comprises the actual doctoral research to be performed, development (and submission) of the thesis, publication of one or more journal articles, presentation at conferences and potentially teaching. The triple constraint principle highlights that any change to one of the constraints will have an impact on one or both of the other constraints. For example, increased scope typically leads to increased time and cost; tight time constraints usually mean that an overrun in activities (such as experimentation) might have a knock-on effect of requiring the scope to be reduced to submit your thesis on time, or increasing the overall amount of time required to complete your PhD. Similarly, a tight budget could mean you cannot gain access to various resources, resulting in either increased time or a reduction in scope. Recently, a fourth component of the project management triangle has been introduced highlighting that along with the three constraints competing with each other, they also interact to form a fourth dimension of quality.If you need to complete your doctoral programme within a specified time frame, then you need to manage your goals and scope mercilessly—do not allow additional research questions or extra experiments to take away precious time. This does not mean that you cannot deviate, but any deviations need to be managed. Remember, whether you wish to remain in scientific research or not, the PhD is a stepping-stone to your future career and not the end goal in itself. Once you have achieved the goals agreed with your supervisor, it is more beneficial for you to write-up your doctoral thesis and move on [2].Good communication is essential in every area of work, but even more so for a PhD as you are simultaneously learning how to research along with doing the research. Often, access to your supervisor is limited by constraints on his/her or your time, which means that clear communication is vital. Do not assume that your supervisor knows every intricate detail of what you are doing; he or she might have a large group in which each member is looking at complementary aspects of a more general topic. It is, therefore, your responsibility to ensure that all your stakeholders—supervisors, postdoc leads and any others involved—know what you are doing and, more importantly, why you are doing it.This is another area in which the apt use of technology can maximize efficiency. Subject to institutional licensing, collaboration tools such as SkillsForge or Evernote can improve communication between stakeholders. For example, meeting minutes, action points to be followed and research results can be uploaded for sharing. Supervisors can then review the material at a convenient time to ensure that they stay up to date with the progress of each student within their research group.As PhD students usually aspire to become research scientists, it is of paramount importance that you learn the correct application of the scientific method and the context in which your work is being done. Before jumping into practical work—wet-lab experiments or computational modelling—it is important to understand the meaning and relevance of your project in relation to existing knowledge and the underlying science. For example, the hypothesis-driven research life cycle in systems biology [3,4]—my own field—advises that computational models should be developed on the basis of wet-lab data relating to the underlying biological system. Almeida-Souza and Baets state that a PhD in science is an opportunity to learn how to tackle problems scientifically and, as such, requires the development of skills in critical thinking, hypothesis formulation and experimental design [5]. I believe that the requirement for these skills is universal across the sciences, and that molecular biosciences and computational systems biology are no different.The serious consideration of scope is necessary in any project, but even more when you are simultaneously project manager, research scientist and key stakeholderTherefore, before the first wet-lab experiment is performed, or the first line of code is written, it is essential that we understand why the experiment is important and what results we might expect to support our initial hypotheses. Furthermore, regarding computational systems biology, I believe that it is also essential for wet-lab and computational researchers to collaborate to ensure both have a consistent understanding of the data and the purpose of the computational model. After all, for the most part, computational models are developed for their predictive capacities and to allow hypothesis generation for subsequent wet-lab experimentation. Baxter et al have extensively covered this area and advocate not only designing the project up-front, but also the need for quality control [6].You need to manage the scope and goals of your PhD mercilessly and, at the same time, be flexible enough to grasp new opportunities. Conversations at conferences, for instance, can open up opportunities for collaboration and take your research in a direction that you had not considered previously. In my case, I was invited to turn a conference paper relating to my masters degree into a full paper for a special issue of a well-known bioinformatics journal. Although it was not related to my doctoral research, the prospect was too good to turn down. I therefore discussed the idea with my PhD supervisor, and once we were in agreement, I updated the project schedule to incorporate this new activity, trying to mitigate as much as possible the resulting slippages to my doctoral research. In essence, I had performed an impromptu risk–reward analysis and decided that the reward that would be gained from publishing this work outweighed the risk of a slight overrun of my PhD thesis. It must be noted that I was lucky in this instance, as my PhD supervisor also supervised the research project during my master''s degree, so a full paper would be beneficial for both of us.A project risk is “an uncertain event or condition, that if it occurs, has an effect on at least one project objective” [1]. The positive side to risks is that the likelihood of their future occurrence can be mitigated by planning in the present. Once a risk is realized, however, and its effects begin to be felt, it has turned into a project issue. The first step in trying to manage risks is their identification. Risk identification in this context is the process of determining which events, if they occurred, would affect your research. In the context of a molecular biosciences PhD, I believe that general risks relate to access to resources, such as people—postdocs and collaborators, for example—reagents, cell lines and shared equipment. For example, if your work uses fluorescent proteins within single cell analysis, how would you be affected if the fluorescence microscope was booked out by another research lab? Similarly, in computational systems biology, if the design process for your computational model requires access to wet-lab data, what would the effect(s) be if this was not available?Once risks are identified, it is important to develop risk response plans. By using the above example of access to a microscope, what should your response be if you cannot gain access? The initial risk response would be to liaise with the other research lab to understand their requirements and ascertain whether you could gain access at a mutually convenient time. Alternatively, another approach might be to work outside normal office hours, either throughout the evenings or on the weekend, subject to health and safety procedures at your institution and your own health and well-being. I believe that a degree of creativity is often required when developing effective risk response plans.A PhD thesis is a hefty document that might run to many hundreds of pages. They are generally not written as a single large document from start to finish, but as chapters. In the molecular biosciences, a thesis consists of an initial literature review early in the doctoral programme, work-in-progress documents for materials and methods, experimental results throughout the middle section, which is followed by analysis and critical evaluation towards the end of your experimental work. Whether through software tools or through your own manual methods, such as keeping a configuration log and keeping a copy of each version of your working documents, it is essential that you maintain an up-to-date repository of all your notes. I have found through experience that it is beneficial to save not only the final versions, but also each of the working drafts of documents generated throughout your PhD. Ideas previously discounted, and thus removed from more recent versions of documents, might once again take centre stage at a later date.The positive side to risks is that the likelihood of their future occurrence can be mitigated by planning in the presentThis can be aided through the development and use of a project library with a logical folder structure to facilitate easy access to documentation. Noble [7] provides an in-depth discussion of organizing your computational biology project—in particular the value of version control—but the concepts are transferable across disciplines. Furthermore, do not forget to back-up your work, and without seeming too pessimistic, back-up your back-up!Finally, look after the most important resource: you. Exercise, diet, alcohol, caffeine and holidays all affect your well-being. Holidays and time away from the lab or office allow you to take a step back from the detail and reflect on your experiences and progress. Sometimes, time off allows you to process issues subconsciously and develop new approaches to overcome problems that you have been tackling for extended periods of time without success. Finally, holidays also help you recharge your batteries and enthusiasm to return to your project with fresh vigour. If you have sensibly and reasonably planned time off alongside your work, you will be able to enjoy it.Although a PhD requires consistent commitment, you simply cannot—and should not—work at full capacity all of the time. Issues arise periodically throughout any project, and if you have no reserves of energy—either mental or physical—you will be unable to tackle them head on with the step change of performance that is required. Furthermore, doctoral research is a marathon and not a sprint; we all experience the symptoms of burnout from time to time, and sometimes it is better to walk away for a short period to recharge than to carry on, become stale, and ultimately slow down.To conclude, I wish you good luck with your doctoral research, and I hope these techniques help you to manage your PhD project through to successful completion.? Open in a separate windowRichard Alun Williams  相似文献   

13.
During my PhD thesis research (1946–1949), I explored the effects of light on the uptake of 32P-labeled inorganic phosphate (Pi) by cells of photosynthetic bacteria and microalgae, and the dynamics of P turnover between low and high molecular weight cell constituents. The results were interpreted as evidence for the conversion of light energy to the chemical energy of phosphorylated compounds. The experimental results also suggested to me that the precursors of the P in DNA bacteriophages of Escherichia coli must be low molecular weight phosphorylated compounds present within the host cells and led to the design of an experiment to determine the conservation of 32P of an infecting phage particle in its numerous progeny. The experiment envisaged was never conducted because phage labeled with 32P of high specific activity showed unexpected loss of viability. Thus, by serendipity, ‘suicide’ of phage due to 32P-β decay was discovered. 32P-decay ‘suicide’ provided a technique that was useful for analysis of phage genetic structure and replication. This memoir describes the unusual circumstances leading to the decisive role of serendipity in revealing an extraordinary phenomenon. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

14.
Three different models: the unstructured mechanistic black-box model, the input–output neural network-based model and the externally recurrent neural network model were used to describe the pyruvate production process from glucose and acetate using the genetically modified Escherichia coli YYC202 ldhA::Kan strain. The experimental data were used from the recently described batch and fed-batch experiments [ Zelić B, Study of the process development for Escherichia coli-based pyruvate production. PhD Thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, Zagreb, Croatia, July 2003. (In English); Zelić et al. Bioproc Biosyst Eng 26:249–258 (2004); Zelić et al. Eng Life Sci 3:299–305 (2003); Zelić et al Biotechnol Bioeng 85:638–646 (2004)]. The neural networks were built out of the experimental data obtained in the fed-batch pyruvate production experiments with the constant glucose feed rate. The model validation was performed using the experimental results obtained from the batch and fed-batch pyruvate production experiments with the constant acetate feed rate. Dynamics of the substrate and product concentration changes was estimated using two neural network-based models for biomass and pyruvate. It was shown that neural networks could be used for the modeling of complex microbial fermentation processes, even in conditions in which mechanistic unstructured models cannot be applied.  相似文献   

15.
Women and men have special needs in rehabilitation. Women''s needs, however, have received far less attention in the scientific community and medical literature. This section, edited by Sandra Cole, PhD,* highlights some of the unique concerns of women who live with physical disabilities.  相似文献   

16.
《Ibis》1997,139(4):722-723
FLEXCHER, F.J.C. 1996. Male and Female Aspects of Sperm Competition in the Zebra Finch, Tueniopygiu guttutu. PhD Thesis. University of Sheffield.
GILBERT, 1,. 1996. Sperm Competiton in the Western Gull. PhD Thesis. University of Sheffield.
LOVELL-MANSBRIDGE, C. 1995. Sperm Competition in the Feral Pigeon Columbn liviu. PhD Thesis. University of Sheffield.
PAKKO IT, D. 1 99 5. Social Organisation and Extra-pair Behaviour in the European Black-billed Magpie Pica pica. PhD Thesis. University of Sheffield.  相似文献   

17.
Abstract

I was delighted and honoured to have been asked to participate in the meeting organised by Nick Quirke to celebrate David Nicholson's achievements in the field of molecular simulation. I was a PhD student with David (and Neville Parsonage) between 1987 and 1990. The experience was sufficiently agreeable that I returned to do a further two years of postdoctoral research with David between 1992 and 1994.  相似文献   

18.
Sauermann H  Roach M 《PloS one》2012,7(5):e36307
Even though academic research is often viewed as the preferred career path for PhD trained scientists, most U.S. graduates enter careers in industry, government, or "alternative careers." There has been a growing concern that these career patterns reflect fundamental imbalances between the supply of scientists seeking academic positions and the availability of such positions. However, while government statistics provide insights into realized career transitions, there is little systematic data on scientists' career preferences and thus on the degree to which there is a mismatch between observed career paths and scientists' preferences. Moreover, we lack systematic evidence whether career preferences adjust over the course of the PhD training and to what extent advisors exacerbate imbalances by encouraging their students to pursue academic positions. Based on a national survey of PhD students at tier-one U.S. institutions, we provide insights into the career preferences of junior scientists across the life sciences, physics, and chemistry. We also show that the attractiveness of academic careers decreases significantly over the course of the PhD program, despite the fact that advisors strongly encourage academic careers over non-academic careers. Our data provide an empirical basis for common concerns regarding labor market imbalances. Our results also suggest the need for mechanisms that provide PhD applicants with information that allows them to carefully weigh the costs and benefits of pursuing a PhD, as well as for mechanisms that complement the job market advice advisors give to their current students.  相似文献   

19.
Furunculosis and vibriosis are diseases that cause severe economic losses in the fish-farming industry. The foregut of the Atlantic salmon (Salmo salar L.) was exposed in vitro to two fish pathogens, Aeromonas salmonicida (causative agent of furunculosis) and Vibrio anguillarum (causative agent of vibriosis), and to one probiotic strain, Carnobacterium divergens, at 6 × 104 or 6 × 106 viable bacteria per milliliter. Histological changes following bacterial exposure were assessed by light and electron microscopy. Control samples (foregut exposed to Ringer’s solution only) and samples exposed only to C. divergens had a similar appearance to intact intestinal mucosal epithelium, with no signs of damage. However, exposure of the foregut to the pathogenic bacteria resulted in damaged epithelial cells, cell debris in the lumen, and disorganization of the microvilli. Co-incubation of the foregut with a pathogen and C. divergens did not reverse the damaging effects caused by the pathogen, although these were alleviated when probiotic bacteria were used. Based on these results, we suggest that the probiotic bacterium, C. divergens, is able to prevent, to some extent, pathogen-induced damage in the Atlantic salmon foregut. I. Salinas thanks Fundacion Seneca for a PhD studentship.  相似文献   

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