Influence of killer strains of Saccharomyces cerevisiae on wine fermentation

The effect of killer strains of Saccharomyces cerevisiae on the growth of sensitive strains during must fermentation was studied by using a new method to monitor yeast populations. The capability of killer yeast strains to eliminate sensitive strains depends on the initial proportion of killer yeasts, the susceptibility of sensitive strains, and the treatment of the must. In sterile filtered must, an initial proportion of 2-6% of killer yeasts was responsible for protracted fermentation and suppression of isogenic sensitive strains. A more variable initial proportion was needed to get the same effect with non-isogenic strains. The suspended solids that remain in the must after cold-settling decreased killer toxin effect. The addition of bentonite to the must avoided protracted fermentation and the suppression of sensitive strains; however, the addition of yeast dietary nutrients with yeast cell walls did not, although it decreased fermentation lag.     

Transformation of Terpenoids in Grape Must by Botrytis cinerea

Experiments were done to investigate the volatile components in botrytized grape must and transformation of terpenoids in terpene-supplemented grape must by Botrytis cinerea. Twenty-eight compounds were identified in the volatile concentrate of botrytized must with a combined gas chromatograph-mass spectrometer. No terpenoids were detected in the concentrate. Linalool or terpinen-4-ol decreased a lot when Botrytis cinerea was cultured in the must with these terpenes for 15 days. In linalool-supplemented botrytized must 9 identified and 3 unidentified terpenes were found, while only geranial was detected in terpinen-4-ol-supplemented botrytized must. Botrytis cinerea did not produce terpenoid in grape must without terpenes, but transformed linalool added to grape must into some other monoterpenes.     

Attractive amplifiers in sexual selection: where efficacy meets honesty

How signals have evolved to convey reliable information is a major issue in the study of animal communication. The handicap principle states that recipients must impose differential costs on signallers. Here, we present an alternative hypothesis, the attractive amplifier hypothesis, according to which recipients acquire reliable information by imposing differential benefits on signallers. The attractive amplifier is a non-informative, low-cost phenotypic trait that allows recipients to increase the amount of reliable information acquired from other informative traits. We present a mating-decision model, in which mate attractiveness depends on the multiplicative-interaction between a trait that is positively correlated with mate quality and its attractive amplifier. The evaluation of both traits is assumed to be prone to error. The model shows that, to be an amplifier of cues, an attractive trait must show two well-known consequences of signal ritualization: it must be conspicuous and it must be perceived as a highly stereotyped trait, that is, it must show a low variation at both the within-individual and the within-population levels.     

Surgical care in the village

The care of people suffering from surgical disease or injury is unique in requiring, even at its simplest level, a certain degree of psychomotor skill and technological support. This cannot be achieved and maintained in isolation with any consistency. Villages must therefore be interdependent and related to supervision from the district hospital. The responsibility for village care rests with the district physician. He must be adequately trained for this purpose and provided with the simple facilities that are required. He extends his reach into the villages through the auxiliary health workers, who must be taught the skills necessary for simple surgical procedures and be trained to stabilize those patients that they cannot treat for transport to the district hospital. Although the skills and facilities required must be determined locally, there is a need to define the broad principles of training and to develop simple and adequate technology at village and district levels.     

抢救成功1例速可眠中毒致重度昏迷呼吸停止54小时病人的体会

我们抢救成活１例因服１００片速可眠致重度昏迷、呼吸停止５４小时的女青年,体会如下：①必须迅速彻底洗胃。②自主呼吸停止时,应立即气管插管。③要适当应用中枢兴奋剂,有利于争取时间进行综合治疗。④要适当应用脱水剂并用利尿剂,以控制脑水肿。⑤必须严格执行昏迷护理常规,维持水电解质平衡,预防合并症。     

Controlling the exotic diseases: 2. Nursing management.

Advance planning can facilitate the care of a patient with an exotic disease who is admitted to a hospital that lacks facilities for high-security isolation. The Department of National Health and Welfare contingency plan for dealing with such patients lacks specific information in a number of areas of medical care, as described in this paper. Consideration must be given to the number of personnel trained and readied for employment, the criteria for selection and special preparation. The protective clothing generally used for hospital isolation procedures is inadequate. Several types of special clothing, including a respirator, are available for total protection of personnel; the clothing may be uncomfortable when worn for long periods, and does restrict movement, vision and communication. All persons entering the isolation suite must change into fully protective clothing, and double layers of clothing are required for direct patient care. All personnel must shower and change before leaving the isolation suite. Suitable facilities for dressing and showering, together with entry and exit routines, must be considered. Hand washing, daily cleaning procedures and disposal of liquid and solid wastes all require special procedures. The social and psychologic problems of patients and their families must also be considered. Preplanning is required to decrease the risks involved in monitoring vital signs and implementing emergency procedures requiring contact with the patient''s blood.     

Somatic cell nuclear transfer efficiency: How can it be improved through nuclear remodeling and reprogramming?

Fertile offspring from somatic cell nuclear transfer (SCNT) is the goal of most cloning laboratories. For this process to be successful, a number of events must occur correctly. First the donor nucleus must be in a state that is amenable to remodeling and subsequent genomic reprogramming. The nucleus must be introduced into an oocyte cytoplasm that is capable of facilitating the nuclear remodeling. The oocyte must then be adequately stimulated to initiate development. Finally the resulting embryo must be cultured in an environment that is compatible with the development of that particular embryo. Much has been learned about the incredible changes that occur to a nucleus after it is placed in the cytoplasm of an oocyte. While we think that we are gaining an understanding of the reorganization that occurs to proteins in the donor nucleus, the process of cloning is still very inefficient. Below we will introduce the procedures for SCNT, discuss nuclear remodeling and reprogramming, and review techniques that may improve reprogramming. Finally we will briefly touch on other aspects of SCNT that may improve the development of cloned embryos.     

pH dependency of the reactions catalyzed by chorismate mutase-prephenate dehydrogenase from Escherichia coli

The variation with pH of the kinetic parameters associated with the mutase and dehydrogenase reactions catalyzed by chorismate mutase-prephenate dehydrogenase has been determined with the aim of elucidating the role that ionizing amino acid residues play in binding and catalysis. The pH dependency of log V for the dehydrogenase reaction shows that the enzyme possesses a single ionizing group with a pK value of 6.5 that must be unprotonated for catalysis. This same group is observed in the V/Kprephenate, as well as in the V/KNAD, profile. The V/Kprephenate profile exhibits a second ionizing residue with a pK value of 8.4 that must be protonated for the binding of prephenate to the enzyme. For the mutase reaction, the V/Kchorismate profile indicates the presence of three ionizing residues at the active site. Two of these residues, with similar pK values of about 7, must be protonated, while the third, with a pK value of 6.3, must be unprotonated. It can be concluded that all three groups are concerned with the binding of chorismate to the enzyme since the maximum velocity of the mutase reaction is essentially independent of pH. This conclusion is confirmed by the finding that the Ki profile for the competitive inhibitor, (3-endo,8-exo)-8-hydroxy-2-oxabicyclo[3.3]non-6-ene-3,5-dicarboxylic acid, shows the same three ionizing groups as observed in the V/Kchorismate profile. By contrast, the Ki profile for carboxyethyldihydrobenzoate shows only one residue, with a pK value of 7.3, that must be protonated for binding of the inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Phenols removal in musts: Strategy for wine stabilization by laccase

The potential of laccase from Trametes versicolor for phenolic removal in must for wine stabilization was evaluated through a combination of an analytical methodology (capillary zone electrophoresis) and kinetics of phenols removal as the total antioxidant potential variation. Total phenolic content, total antioxidant potential and polyphenols were monitored from 0 to 3 h of must treatment. The results indicated that the treatment of a red must with laccase affect mainly the phenolic compounds responsible for the must antioxidant properties. The treatment of white musts with laccase showed higher reduction in total phenol than in the total antioxidant potential. Phenol degradation by laccase was very fast for catechins, and slowly for stilbenes (cis- and trans-resveratrol) and derivatives of cinnamic (ferulic and caffeic) and benzoic (syringic, vanillic, and gallic) acids. It is possible to conclude in this case that the use of laccase in white wines is perfectly feasible. This would allow softer and ecologically correct treatments, which would diminish the cost of processing and avoid deterioration of wines for long storage times.     

Re-aiming the canon.

Although it is unlikely that the national goals for educational reform--such as that, by the year 2000, U.S. students will be first in the world in science and mathematics achievement--can be achieved, a vigorous effort must be made to reach those goals as rapidly as possible. Reform will come not from a massive expansion of what we now do but from a basic shift in the manner in which we educate students in grades K-16 in the sciences and mathematics. Important elements in that basic shift must include an increase in teaching of science, mathematics, and technology (SMT), to about 20%-25% of the curriculum; SMT must include rich hands-on experiences, with an emphasis on concepts and understanding, rather than on facts and memorization, and on how science as a way of knowing differs from other ways of knowing; SMT must consider human problems; and SMT must deal with the basic problem facing humanity--how we must adjust our behavior so as not to exceed, on a worldwide basis, the carrying capacity of the environment.     

Acid-base catalysis in the argininosuccinate lyase reaction

The pH variation of the kinetic parameters, Vmax and V/K, was examined for the forward and reverse reaction of bovine liver argininosuccinate lyase. In the forward reaction the Vmax profile showed one group that must be unprotonated for activity over the pH range 5-10. The V/K profile for argininosuccinate showed one group that must be unprotonated and two groups that must be protonated for activity. The Vmax profile for the reverse reaction showed only one group that must be protonated for activity. These results support the proposal that catalysis is facilitated in the forward reaction by a general base that abstracts a proton from C-3 of argininosuccinate and a general acid that donates a proton to the guanidinium nitrogen during carbon-nitrogen bond cleavage. The enzyme is completely inactivated by diethyl pyrocarbonate or a water-soluble carbodiimide at pH 6. These experiments suggest that a histidine and a carboxyl group are at or near the active site and are essential for catalytic activity. The observed shifts of the pH profiles of the forward reaction with temperature and organic solvent (25% dioxane) were also consistent with a histidine and carboxylate group.     

Challenges of the medical entomology for the surveillance in public health in Colombia: reflections on the state of malaria

The relevance of the medical entomology was considered with respect to current framework of malaria control programs in Colombia. A responsibility is indicated for balancing control efforts along with providing information on the malaria vectors. This knowledge must be acquired in order to focus the related activities that are required. The malaria control program must be based on results of local entomological surveillance, and the data must be in a form to give practical answers to questions regarding the control program. Difficulties in undertaking the required studies are described, particularly regarding the taxonomic identification of Colombian Anopheles in Colombia and which of these can be incriminated as malaria vectors.     

Mind the sustainability gap

Despite increasing efforts to reach sustainability, key global biophysical indicators such as climate change and biodiversity loss continue to deteriorate rather than improve. Ongoing failure to move towards sustainability calls into question the focus of current research and policy. We recommend two strategies for progress. First, sustainability must be conceptualized as a hierarchy of considerations, with the biophysical limits of the Earth setting the ultimate boundaries within which social and economic goals must be achieved. Second, transdisciplinary research programs must confront key normative questions facing modern consumer societies. The humanities should have a key role in such programs. Assisted by these strategies, ambitious targets that realistically reflect the biophysical limits of the life-support system of the Earth must be set and relentlessly worked towards.     

Effect of must characteristics on the diversity of Saccharomyces strains and their prevalence in spontaneous fermentations

Aims: The aim of this study was to investigate whether grapevine variety and must characteristics influence the diversity of Saccharomyces strains and their prevalence during spontaneous fermentations. Methods and results: Musts from different grapevine varieties, all of them autochthonous from Galicia, were used to perform spontaneous fermentations. Yeasts were isolated from the must and at the beginning, in the middle and at the end of fermentations. Those yeasts identified as Saccharomyces were characterized at the strain level by analysis of mtDNA‐RFLP. The results showed a low diversity of Saccharomyces strains, which was related to must sugar content and total acidity. Moreover, from a total of 44 different Saccharomyces strains, only eleven of them appeared at frequencies higher than 20% and were able to lead fermentations. A significant correlation between yeast strains and must acidity was observed, with the predominance of certain strains at high acidity values. Conclusions: Must characteristics, such as sugar content and acidity, influence the Saccharomyces strains diversity and the leader strains during fermentation. Significance and Impact of the Study: These results showed the adaptation of certain Saccharomyces strains to must with specific characteristics; this may be considered by winemakers for yeast inocula selection. Our findings have special relevance because this is the first study carried out in Galicia dealing with the influence of must properties on yeast strains that control fermentations.     

Worker rehabilitation programs. Separating fact from fiction.

A few worker rehabilitation programs have had outstanding success in improving ability to function for persons with occupational back pain. Local programs must show that they have similar success. Because the definitions of terms such as "back school," "work hardening," and "functional restoration" are blurred at a local level, the choice of a program for an individual patient must depend primarily on the program''s demonstrated success rate with similar patients. The chances of returning to work decrease as a function of time after injury. Therefore, referring physicians, insurers, and employers must be provided with information regarding results in terms of acute (0 to 6 weeks), subacute (7 to 12 weeks), and chronic (more than 12 weeks) back pain. Other important variables include selection criteria, program cost, and dropout rate. We advocate standardized reporting of such data for all worker rehabilitation programs. A model "report to consumers," described here, is a minimal obligation. The validity of a number of important internal quality assurance issues is uncertain. Ethical and legal pressures must be recognized.     

Biological constraints on orthographic representation

This paper sets out five constraints that a psychologically efficient orthography must meet. The first four principles are that (1) the elements of the orthography must be easy to discriminate; (2) it must be possible to write the code quickly, without elaborate technology; (3) the code must permit unambiguous, fast and fail-safe access to the meanings of messages; (4) the system as a whole should be learnable without undue expenditure of time and effort. A fifth principle, that the dimensions of formal and semantic similarity in an orthography should be orthogonal, is argued to be the best way of ensuring that reading errors are kept to a minimum. Evidence for the last principle is derived from the study of errors made by subjects with acquired dyslexia.     

Tracing and control of raw materials sourcing for vaccine manufacturers

The control of the raw materials used to manufacture vaccines is mandatory; therefore, a very clear process must be in place to guarantee that raw materials are traced. Those who make products or supplies used in vaccine manufacture (suppliers of culture media, diagnostic tests, etc.) must apply quality systems proving that they adhere to certain standards. ISO certification, Good Manufacturing Practices for production sites and the registration of culture media with a ‘Certificate of Suitability’ from the European Directorate for the Quality of Medicines and Healthcare are reliable quality systems pertaining to vaccine production. Suppliers must assure that each lot of raw materials used in a product that will be used in vaccine manufacture adheres to the level of safety and traceability required. Incoming materials must be controlled in a single ‘Enterprise Resource Planning’ system which is used to document important information, such as the assignment of lot number, expiration date, etc. Ingredients for culture media in particular must conform to certain specifications. The specifications that need to be checked vary according to the ingredient, based on the level of risk.The way a raw material is produced is also important, and any aspect relative to cross-contamination, such as the sanitary measures used in producing and storing the raw material must be checked as well. In addition, suppliers can reduce the risk of viral contamination of raw materials by avoiding purchases in countries where a relevant outbreak is currently declared.     

Tests and procedures for diagnosis of poisoning in sheep

Poisoning cases in sheep must be addressed with special consideration, due to the particularities of this species, taking into consideration the epidemiology of the habitat area and the diet selection. The investigation must encompass a wide range of expertise and should lead to piecing together of a ‘diagnostic puzzle’, which would include: determination of a complete case history, clinical signs, clinicopathological findings, post-mortem findings, results from chemical analyses and, occasionally, bioassay findings. Although these diagnostic tools are not much different than diagnostics currently available for other animal species, special care must be taken when sampling for a suspected toxicant in sheep.