Synthesis and characterization of multiply-tyrosinated, multiply-iodinated somatostatin analogs.

Radio-labeled somatostatin analogs have recently gained popularity as agents useful in intraoperative tumor localization, external scintigraphy and in situ radiotherapy. We have synthesized and characterized a series of novel N-terminally extended multiply-tyrosinated somatostatin analogs that possess high binding affinity for somatostatin receptors, exhibit biological activity comparable to the native peptide and retain these characteristics after iodination. These analogs can be radio-iodinated to high specific activities. Following radioiodination, these analogs exhibit minimal radiolysis and may be clinically useful for tumor localization, scanning and therapy.     

Factors influencing the reaction of mountain goats towards all-terrain vehicles

The increasing popularity of recreational activities in the wild has led to concerns about their potential impacts on wildlife. All-terrain vehicles (ATVs) often bring people into wildlife habitats, where they may disturb animal populations. We assessed the influence of ATVs on the behavior of mountain goats (Oreamnos americanus) in a long-term study population at Caw Ridge, Alberta, Canada. We used multinomial models containing environment-, disturbance-, and group-related factors, to evaluate the response of mountain goats to the approach of ATVs. Goats were moderately to strongly disturbed by ATVs 44% of the time, and disturbance levels were mainly influenced by the direction and speed of the approaching vehicles. Environment- or group-related factors (e.g., time of year, distance to escape terrain, group size or type) did not affect mountain goat responses to ATVs. Because goat reactions were influenced by disturbance-level factors, we propose mitigating measures regarding the use of ATVs in the wild to minimize the disturbance to mountain goats, and potentially other alpine ungulates. © 2012 The Wildlife Society.     

Question Popularity Analysis and Prediction in Community Question Answering Services

With the blooming of online social media applications, Community Question Answering (CQA) services have become one of the most important online resources for information and knowledge seekers. A large number of high quality question and answer pairs have been accumulated, which allow users to not only share their knowledge with others, but also interact with each other. Accordingly, volumes of efforts have been taken to explore the questions and answers retrieval in CQA services so as to help users to finding the similar questions or the right answers. However, to our knowledge, less attention has been paid so far to question popularity in CQA. Question popularity can reflect the attention and interest of users. Hence, predicting question popularity can better capture the users’ interest so as to improve the users’ experience. Meanwhile, it can also promote the development of the community. In this paper, we investigate the problem of predicting question popularity in CQA. We first explore the factors that have impact on question popularity by employing statistical analysis. We then propose a supervised machine learning approach to model these factors for question popularity prediction. The experimental results show that our proposed approach can effectively distinguish the popular questions from unpopular ones in the Yahoo! Answers question and answer repository.     

Injuries and deaths associated with off-road recreational vehicles among children in Manitoba.

Injuries and deaths associated with off-road recreational vehicles are of increasing concern in North America. We reviewed all hospital admissions and deaths attributed to these vehicles in Manitoba from April 1979 to April 1985 among children 16 years of age or younger. Of the 693 hospital admissions and deaths 480 were associated with motorbikes, snowmobiles or all-terrain vehicles (ATVs). The incidence of injuries resulting from snowmobile and dirtbike accidents remained stable over the study period; however, there was an almost exponential increase in the number of admissions because of ATV-related injuries. There were 21 deaths during the study period. Preventive measures through legislation are necessary to reduce the numbers of injuries and deaths; these include mandatory registration, licensing and enhanced safety regulations.     

Large-Scale Assessment of the Effect of Popularity on the Reliability of Research

Based on theoretical reasoning it has been suggested that the reliability of findings published in the scientific literature decreases with the popularity of a research field. Here we provide empirical support for this prediction. We evaluate published statements on protein interactions with data from high-throughput experiments. We find evidence for two distinctive effects. First, with increasing popularity of the interaction partners, individual statements in the literature become more erroneous. Second, the overall evidence on an interaction becomes increasingly distorted by multiple independent testing. We therefore argue that for increasing the reliability of research it is essential to assess the negative effects of popularity and develop approaches to diminish these effects.     

Induction of cytotoxic T lymphocytes in vivo with protein antigen entrapped in membranous vehicles.

Intravenous administration of APC such as splenocytes loaded with a soluble protein Ag has been shown to prime for an Ag-specific CTL response. It is thought that the APC directly presents loaded Ag in a MHC-restricted manner. However, it is demonstrated in this study that allogeneic splenocytes, MHC-free RBC, and even synthetic lipid vesicles (liposomes) after loading with OVA can elicit an OVA-specific and MHC-restricted CTL response. Biodistribution studies of these Ag-associated vehicles showed that the liver, spleen, and lung were the major organs responsible to scavenge these carriers, suggesting that the monocyte-macrophage system was involved in the Ag presentation for CTL. Depletion of macrophages by a specific macrophage killer, Cl2MDP, containing liposomes, abolished the CTL induction by immunization with OVA Ag carried by these vehicles except the induction by syngeneic splenocytes. Thus, the syngeneic splenocytes present Ag directly to the T cells, but other membranous vehicles carry the Ag to the host APC including macrophages, which then present it to the T cells. These results indicate that formulation of an Ag in membranous/colloidal vehicles may be a way to prime for a CTL response.     

Saying it with genes,species and habitats: biodiversity education and the role of zoos

This paper considers the role of zoological gardens as vehicles for teaching about biodiversity and conservation. The general importance of conservation and biodiversity education is outlined in the context of Agenda 21 and the Global Biodiversity Strategy, and the unique niche of zoo education for meeting these challenges is defined. This includes the exhibition of real live animals, accessibility. immediacy, popularity, egalitarianism and the unique combination of strengths and resources offered by zoo education departments. Effective zoo education for biodiversity conservation depends on answering certain criticisms (including behavioural distortion, ecological context and people/animal relationships); working within the available resource framework; and careful strategic planning that considers appropriate messages, target audiences and communication methods. Future zoo education trends might include developing the unique niche; teaching about zoos' role in interactive management; and the contribution of zoo networks to education.     

Evidence that retroviruses integrate into post-replication host DNA.

We have studied the question of whether a retrovirus integrates into the chromosomal DNA of the host cell before or after the DNA is replicated during the S phase of the cell cycle. We have infected single NIH-3T3 cells with BAG, a replication-incompetent retroviral vector which encodes the lacZ gene, then observed the clones derived from these cells to discover whether all the cells carry a copy of the proviral DNA. We have discovered that only half of the progeny of an infected cell carries a copy of the provirus. This indicates that the virus only integrates into post-replication DNA. We discuss the implications of this result for applications of retroviruses, such as gene therapy and cell lineage, which use them as vehicles for gene transfer into stem cells.     

Gene fusion vehicles for the analysis of gene expression in Rhizobium meliloti.

A set of plasmid cloning vehicles was developed to facilitate the construction of gene or operon fusions in Rhizobium meliloti. The vehicles also contain a broad-host-range replicon and could be introduced into bacteria either by transformation or by transduction, using bacteriophage P2. Insertion of foreign DNA into a unique restriction endonuclease cleavage site promotes the synthesis of either the Escherichia coli lactose operon or the kanamycin phosphotransferase gene from transposon Tn5. Expression of the lactose operon could be detected by observing the color of Rhizobium colonies on medium that contained a chromogenic indicator. We also determined the growth conditions that make it possible to select either for or against the expression of the E. coli lactose operon in R. meliloti. Recombinant plasmids were constructed by inserting MboI restriction fragments of R. meliloti DNA into one of the vehicles, pMK353 . Expression of beta-galactosidase by a number of these recombinants was measured in both R. meliloti and E. coli.     

Expression vehicles used in recombinant DNA technology

We survey cloning vehicles whose function is to carry and express a gene in host cells including Escherichia coli, Saccharomyces cerevisiae and mammalian cells. In E. coli these include vehicles based on the lac operon, the trp operon, the rho leftward operon, and the recA gone; open reading frame cloning vehicles are also discussed, as are steps that can be taken to extrude a gene product from the cell and the use of plasmids with runaway replication. In S. cerevisiae we discuss vehicles based on the PGK gene, the ADH1 gene, the acid phosphatase gene and the GAL1-GAL10 gene cluster. In mammalian cells we discuss vehicles based on SV40 promoters, the metallothionein gene, retroviral LTR promoters, bovine papilloma virus and vaccinia virus.     

New IS10 transposition vectors based on a gram-positive replication origin.

We describe below a set of plasmid-based vehicles which can be used for delivery of IS10-derived transposons into Gram- bacteria. These vehicles replicate via a Gram+ plasmid origin that is inactive in Escherichia coli; they are easily maintained in Bacillus subtilis. Transposons are introduced by electroporation or transformation with the plasmid, and as in previous delivery systems, transpositions are selected with the appropriate antibiotic. This system should be particularly useful in situations where the standard delivery vehicles, based on bacteriophage lambda, are inappropriate. The system described incorporates a number of useful features: a variety of antibiotic markers (Er, Cm, Km or Tc), a polylinker containing restriction sites for rare-cutting endonucleases to facilitate physical mapping of chromosomal insertions, a mutant transposase that confers a relaxation in insertion specificity and positioning of the transposase-encoding gene outside of the transposing segment to ensure the stability of insertions once isolated.     

Dog Movie Stars and Dog Breed Popularity: A Case Study in Media Influence on Choice

Fashions and fads are important phenomena that influence many individual choices. They are ubiquitous in human societies, and have recently been used as a source of data to test models of cultural dynamics. Although a few statistical regularities have been observed in fashion cycles, their empirical characterization is still incomplete. Here we consider the impact of mass media on popular culture, showing that the release of movies featuring dogs is often associated with an increase in the popularity of featured breeds, for up to 10 years after movie release. We also find that a movie''s impact on breed popularity correlates with the estimated number of viewers during the movie''s opening weekend—a proxy of the movie''s reach among the general public. Movies'' influence on breed popularity was strongest in the early 20^th century, and has declined since. We reach these conclusions through a new, widely applicable method to measure the cultural impact of events, capable of disentangling the event''s effect from ongoing cultural trends.     

Adaptive measurement method for data popularity in distributed systems

Distributed systems provide geographically distributed resources for large-scale applications while managing large volumes of data. In this context, replication of data in several sites of the system is an effective solution for achieving interesting performances. A number of data replication strategies have been proposed in the literature. Data popularity is one of the most important parameters taken into consideration by these strategies. It analyzes the historic of the data access pattern, and provides predictions for future data requests. However, measuring data popularity is a challenging task because there are several factors that contribute to the evaluation of data popularity. In this paper, a new adaptive measurement for data popularity in distributed systems is proposed. The proposed measurement covers all factors taken into consideration by previous work of the literature. It also takes into consideration new factors to deal with the dynamic nature of the system so it can adapt to any access pattern. We show that the exploitation of our measurement improves the performances of replication strategies, while offering the possibility to use the data popularity parameter in new contexts in replication management.     

Center Finding in E. coli and the Role of Mathematical Modeling: Past,Present and Future

We review the key role played by mathematical modeling in elucidating two center-finding patterning systems in Escherichia coli: midcell division positioning by the MinCDE system and DNA partitioning by the ParABS system. We focus particularly on how, despite much experimental effort, these systems were simply too complex to unravel by experiments alone, and instead required key injections of quantitative, mathematical thinking. We conclude the review by analyzing the frequency of modeling approaches in microbiology over time. We find that while such methods are increasing in popularity, they are still probably heavily under-utilized for optimal progress on complex biological questions.     

A Study of Statistical Methods for Function Prediction of Protein Motifs

Automatic discovery of new protein motifs (i.e. amino acid patterns) is one of the major challenges in bioinformatics. Several algorithms have been proposed that can extract statistically significant motif patterns from any set of protein sequences. With these methods, one can generate a large set of candidate motifs that may be biologically meaningful. This article examines methods to predict the functions of these candidate motifs. We use several statistical methods: a popularity method, a mutual information method and probabilistic translation models. These methods capture, from different perspectives, the correlations between the matched motifs of a protein and its assigned Gene Ontology terms that characterise the function of the protein. We evaluate these different methods using the known motifs in the InterPro database. Each method is used to rank candidate terms for each motif. We then use the expected mean reciprocal rank to evaluate the performance. The results show that, in general, all these methods perform well, suggesting that they can all be useful for predicting the function of an unknown motif. Among the methods tested, a probabilistic translation model with a popularity prior performs the best.     

Patterns of maxillofacial injuries in powered watercraft collisions

Because of the widespread popularity of water sports, plastic and reconstructive surgeons can expect to manage an increasing number of injuries associated with these activities, particularly those related to powered watercraft vehicles. Although seat belts for motorists and helmets for motorcyclists may be efficacious, such devices currently do not serve a similar role in powered watercraft sports. In this study, a retrospective chart review of 194 consecutive patients who presented to the University of Miami/Jackson Memorial Hospital (Level I trauma center) as a result of powered watercraft collisions is presented. The purpose of this investigation was to assess the incidence, cause, demographics, and available management options for head and neck injuries secondary to powered watercraft. Identified were 194 patients who presented because of watersports-related injuries during the period January 1, 1991, through December 31, 1996. From this group, 81 patients (41.8 percent) sustained injuries directly attributable to powered watercraft collisions, including 41 personal watercraft collisions (50.6 percent), 39 boat collisions (48.1 percent), and 1 airboat collision (1.2 percent). The patient population, as expected, tended to be young and male with an average age of 29 years (range, 8 to 64 years old). Interestingly, 41 of the patients (50.6 percent) who presented to this trauma center as a result of powered watercraft collisions also sustained associated head and neck trauma. Of 74 injuries 24 were facial fractures (32.4 percent), 18 were facial lacerations (24.3 percent), 14 were closed head injuries (18.9 percent), 8 were skull fractures (10.8 percent), 4 were scalp lacerations (5.4 percent), 4 were C-spine fractures (5.4 percent), 1 was an ear laceration (1.4 percent), and 1 was a fatality (1.4 percent). Le Fort fractures were the most commonly identified facial fracture in this series. The number of these injuries seen in hospital emergency rooms will most likely increase in the future as the popularity of water-related recreational activities becomes even more widespread. Based on these findings, it is strongly recommended that future efforts be directed toward the prevention of these injuries through patient education and the eventual development of efficacious and safe protective equipment.     

Ecological correlates of the popularity of birds and butterflies in Internet information resources

The success of conservation programs depends on using appropriate methods to demonstrate the importance of conservation to society. For example, flagship species are among the key marketing tools to motivate public support. However, they are rarely selected in a systematic, manner. In this study we addressed the issue of the colonization of human information resources by birds and butterflies in the context of wildlife conservation. We used a simple method to measure the popularity of species based on Google browsing and made an attempt to link biological characteristics of the species with their popularity in human information resources. Biological traits of species contributed significantly to explaining the occupancy (invasion) of cyberspace by the species. Commonness and body size of the species appeared to be the most informative predictors of their Google score. We believe that these results may be used by conservation organizations to assist in the selection of flagship/charismatic species, and their use in logos, for TV programs or for other public presentations. Moreover, we showed that some biological traits can affect the popularity of wildlife in society and in virtual resources.     

Enhancement of phage-mediated gene transfer by nuclear localization signal

The cell membrane and the nuclear membrane are two major barriers hindering the free movement of various macromolecules through animal cells. Nevertheless, some proteins can actively bypass these barriers by dint of intrinsic peptidic signals, so incorporation of these signals might improve the efficacy of artificial gene delivery vehicles. We examined the role of the nuclear localization signal (NLS) in gene transfer, using recombinant lambda phage as a model of the polymer/DNA complexes. We prepared a lambda phage displaying a 32-mer NLS of SV40 T antigen on its surface (NLS phage), and found that this NLS phage, delivered into the cytoplasm by appropriate devices, has higher affinity for the nucleus and induces the expression of encapsulated marker genes more efficiently than does the wild-type phage. This suggests that the 32-mer NLS peptide will become a practical tool for artificial gene delivery vehicles with enhanced nuclear targeting activity.     

Reproduction in llamas and alpacas: a review

In this review we attempt to compile and summarize the diverse and often contradictory material presented on the reproduction of llamas and alpacas (hereafter referred to as lamoids). Lamoids have recently gained international popularity, and theriogenologists are often asked to intervene in clinical management of reproductive problems of these animals. We therefore present a discussion of the reproductive anatomy, physiology, and behavior of llamas as well as the follicular dynamics as observed with ultrasonography. The nonsurgical embryo transfer procedure and the nutrient requirements of llamas are also discussed.     

End-of-Life Infrastructure Economics for "Clean Vehicles" in the United States

Rising fuel prices and concern over emissions are prompting automakers and legislators to introduce and evaluate "clean vehicles" throughout the United States. Hybrid electric vehicles (HEVs) are now on the roads, electric vehicles (EVs) have been test marketed, and niche vehicles such as high-fuel-economy microcars are being considered for introduction. As these vehicles proliferate and mature, they will eventually reach their end of life (EOL). In the United States, an extensive recycling infrastructure exists for conventional, internal combustion engine (ICE) vehicles. Its primary constituents are the disassembler and the shredder. These industries, as well as battery recyclers, are expected to play integral roles in the EOL processing of clean vehicles.
A model of the automobile-recycling infrastructure and goal programming techniques are used to assess the materials streams and process profitabilities for several different clean vehicles. Two-seat EVs with lead-acid or NiMH batteries are compared with two- and four-seat HEVs and microcars. Changes to the nonferrous content in the vehicle bodies are explored and compared for the effect on processing profit-ability. Despite limitations associated with the linearity of goal programming techniques, application of this tool can still provide informative first-order results. Results indicate that although these clean vehicles may not garner the same profit levels as conventional ICE vehicles, they are profitable to process if there are markets for parts and if there are sufficient quantities of nonferrous materials.