bluuebunny/crossref_metadata_2025 huggingface dataset:
Myocardial pressure overload induces systemic inflammation through endothelial cell IL-33
Authors: Chen Wei-Yu , Hong Jaewoo , Gannon Joseph , Kakkar Rahul , Lee Richard T.
Published: May 2015

Significance

The association of hypertension and inflammation is clear, but mechanisms for this human finding remain elusive. The experiments in this article demonstrate that a highly local intramyocardial signaling pathway through ST2, the receptor for the proinflammatory cytokine interleukin 33 (IL-33), regulates the heart’s response to pressure overload. By generating and using new conditional deletion mice, we identified endothelial cells as the major source of systemic circulating IL-33. Our study reveals that endothelial cell secretion of IL-33 is crucial for translating myocardial pressure overload into a selective systemic inflammatory state.
Interleukin-6/interleukin-21 signaling axis is critical in the pathogenesis of pulmonary arterial hypertension
Authors: Hashimoto-Kataoka Takahiro , Hosen Naoki , Sonobe Takashi , Arita Yoh , Yasui Taku , Masaki Takeshi , Minami Masato , Inagaki Tadakatsu , Miyagawa Shigeru , Sawa Yoshiki , Murakami Masaaki , Kumanogoh Atsushi , Yamauchi-Takihara Keiko , Okumura Meinoshin , Kishimoto Tadamitsu , Komuro Issei , Shirai Mikiyasu , Sakata Yasushi , Nakaoka Yoshikazu
Published: May 2015

Significance

Pulmonary arterial hypertension (PAH) is a serious disease characterized by vascular remodeling in pulmonary arteries. Although an elevated IL-6 serum level correlates with poor prognosis of PAH patients, it is unclear how IL-6 promotes PAH. Here we identified IL-21 as a downstream target of IL-6 signaling in PAH. In mice with hypoxia-induced pulmonary hypertension (HPH), Th17 cells and M2 macrophages accumulate in the lungs after hypoxia exposure. IL-21 primarily derived from Th17 cells promotes M2 macrophage polarization. Consistently, IL-21 receptor-deficient mice show resistance to HPH with no accumulation of M2 macrophages in the lungs. IL-21 and M2 macrophage markers were upregulated in the lungs of patients with end-stage idiopathic PAH. These findings suggest promising therapeutic strategies for PAH targeting IL-6/IL-21–signaling axis.
Obstruction of adaptation in diploids by recessive, strongly deleterious alleles
Authors: Assaf Zoe June , Petrov Dmitri A. , Blundell Jamie R.
Published: May 2015

Significance

A deleterious mutation that is recessive is hidden in individuals containing only one copy (i.e., heterozygotes); however, individuals containing two copies (i.e., homozygotes) suffer negative effects. This class of mutation is responsible for a number of human genetic disorders, including cystic fibrosis and Tay-Sachs, in addition to causing the widespread phenomenon of inbreeding depression. Evidence suggests that recessive deleterious mutations may be abundant in nature, likely due to their ability to persist for long timescales at moderate frequencies. It is thus possible that when an adaptive mutation occurs, it lands on a chromosome containing a recessive deleterious mutation. We propose a model for this and find that recessive deleterious mutations can significantly slow adaptation and alter signatures of adaptation.
Mechanism of pyranopterin ring formation in molybdenum cofactor biosynthesis
Authors: Hover Bradley M. , Tonthat Nam K. , Schumacher Maria A. , Yokoyama Kenichi
Published: May 2015

Significance

The molybdenum cofactor (Moco) is an enzyme cofactor critical for the survival of almost all organisms from all kingdoms of life, and its biosynthesis is associated with various medical conditions such as inheritable human diseases and bacterial pathogenesis. The characteristic pyranopterin backbone of Moco is formed by the action of two enzymes, MoaA and MoaC (molybdenum cofactor biosynthesis protein A and C, respectively). Conventionally, MoaA was considered responsible for the majority of the transformation. In contrast to this view, the combined studies reported here revealed that it is MoaC that is responsible for the majority of the rearrangement reaction required for Moco pyranopterin backbone formation. Based on the conservation of MoaC and its catalytic residues, the mechanism of pyranopterin ring formation is likely conserved among all organisms.
Supplementary feeding restructures urban bird communities
Authors: Galbraith Josie A. , Beggs Jacqueline R. , Jones Darryl N. , Stanley Margaret C.
Published: May 2015

Significance

Bird feeding is essentially a massive global supplementary feeding experiment, yet few studies have attempted to explore its ecological effects. In this study we use an in situ experimental approach to investigate the impacts of bird feeding on the structure of local bird assemblages. We present vital evidence that bird feeding contributes to the bird community patterns we observe in urban areas. In particular, the study demonstrates that common feeding practices can encourage higher densities of introduced birds, with potential negative consequences for native birds.
Cahokia’s emergence and decline coincided with shifts of flood frequency on the Mississippi River
Authors: Munoz Samuel E. , Gruley Kristine E. , Massie Ashtin , Fike David A. , Schroeder Sissel , Williams John W.
Published: May 2015

Significance

Our paper evaluates the role that flooding played in the emergence and decline of Cahokia—the largest prehistoric settlement in the Americas north of Mexico that emerged in the floodplain of the Mississippi River around A.D. 1050. We use sediment cores to examine the timing of major Mississippi River floods over the last 1,800 y. These data show that Cahokia emerged during a period of reduced megaflood frequency associated with heightened aridity across midcontinental North America, and that its decline and abandonment followed the return of large floods. We conclude that shifts in flood frequency and magnitude facilitated both the formation and the breakdown of Cahokia and may be important factors in the declines of other early agricultural societies.
Electric-field–induced assembly and propulsion of chiral colloidal clusters
Authors: Ma Fuduo , Wang Sijia , Wu David T. , Wu Ning
Published: May 2015

Significance

Although colloids have been used as molecular analogues for understanding how simple building blocks can assemble into functional materials, they are mostly spherical with isotropic properties. We are still far from truly accessing the diversity of structures desired for either fundamental understanding or technological application. Here, we report the electric-field–directed assembly of asymmetric colloids into clusters that exhibit a ubiquitous type of symmetry in nature: the chirality. We further demonstrate that the chirality induces unbalanced hydrodynamic flow, which causes rotational propulsion of chiral clusters that are fully dictated by their handedness. Both the assembly and propulsion mechanisms discovered can be universal and applied to other types of asymmetric particles. They are also useful in modeling active matter and making microengines.
Drosophila
Ncd reveals an evolutionarily conserved powerstroke mechanism for homodimeric and heterodimeric kinesin-14s
Authors: Zhang Pengwei , Dai Wei , Hahn Juergen , Gilbert Susan P.
Published: May 2015

Significance

Kinesin molecular motors couple ATP turnover to force production to generate microtubule-based movement and microtubule dynamics. Kinesin-14s are unique in that they are nonprocessive, bind to adjacent microtubule protofilaments rather than step along a single protofilament as observed for processive kinesins, and use a powerstroke mechanism to slide microtubules. Earlier studies proposed that only one head of the Ncd dimer interacts with the microtubule to drive the ATP-promoted powerstroke and therefore only one ATP turnover was required. The results presented here challenge the one head/one ATP turnover hypothesis and define a common pathway for Kar3Vik1, Kar3Cik1, and Ncd. These findings are significant because they reveal that the key principles for force generation by kinesin-14s are conserved from yeast to higher eukaryotes.
Modeling malaria genomics reveals transmission decline and rebound in Senegal
Authors: Daniels Rachel F. , Schaffner Stephen F. , Wenger Edward A. , Proctor Joshua L. , Chang Hsiao-Han , Wong Wesley , Baro Nicholas , Ndiaye Daouda , Fall Fatou Ba , Ndiop Medoune , Ba Mady , Milner Danny A. , Taylor Terrie E. , Neafsey Daniel E. , Volkman Sarah K. , Eckhoff Philip A. , Hartl Daniel L. , Wirth Dyann F.
Published: May 2015

Significance

Traditional methods for estimating malaria transmission based on mosquito sampling are not standardized and are unavailable in many countries in sub-Saharan Africa. Such studies are especially difficult to implement when transmission is low, and low transmission is the goal of malaria elimination. Malaria-control efforts in Senegal have resulted in changes in population genomics evidenced by increased allele sharing among parasite genomes, often including genomic identity between independently sampled parasites. Fitting an epidemiological model to the observed data indicates falling transmission from 2006–2010 with a significant rebound in 2012–2013, an inference confirmed by incidence data. These results demonstrate that genomic approaches may help monitor transmission to assess initial and ongoing effectiveness of interventions to control malaria.
Sample and population exponents of generalized Taylor’s law
Authors: Giometto Andrea , Formentin Marco , Rinaldo Andrea , Cohen Joel E. , Maritan Amos
Published: May 2015

Significance

Taylor’s law (TL) has been verified very widely in the natural sciences, information technology, and finance. The widespread observation of TL suggests that a context-independent mechanism may be at work and stimulated the search for processes affecting the scaling of population fluctuations with population abundance. We show that limited sampling may explain why TL is often observed to have exponentb=2. Abrupt transitions in the TL exponent associated with smooth changes in the environment were recently discovered theoretically and comparable real-world transitions could harm fish populations, forests, and public health. Our study shows that limited sampling hinders the anticipation of such transitions and provides estimates for the number of samples required to reveal early warning signals of abrupt biotic change.
CD4 mimetics sensitize HIV-1-infected cells to ADCC
Authors: Richard Jonathan , Veillette Maxime , Brassard Nathalie , Iyer Shilpa S. , Roger Michel , Martin Loïc , Pazgier Marzena , Schön Arne , Freire Ernesto , Routy Jean-Pierre , Smith Amos B. , Park Jongwoo , Jones David M. , Courter Joel R. , Melillo Bruno N. , Kaufmann Daniel E. , Hahn Beatrice H. , Permar Sallie R. , Haynes Barton F. , Madani Navid , Sodroski Joseph G. , Finzi Andrés
Published: May 2015

Significance

The prevention of HIV-1 transmission and progression likely requires approaches that can specifically eliminate HIV-1-infected cells. Rationally designed CD4-mimetic compounds (CD4mc) have been shown to efficiently inhibit viral entry and sensitize HIV-1 particles to neutralization by otherwise nonneutralizing CD4-induced antibodies. Here we found that CD4mc can also sensitize HIV-1-infected cells to antibody-dependent cell-mediated cytotoxicity (ADCC). Indeed, CD4mc induced the CD4-bound conformation of HIV-1 envelope glycoproteins, exposing CD4-induced epitopes recognized by easy-to-elicit antibodies present in sera, cervicovaginal lavages, and breast milk from HIV-1-infected individuals. Importantly, we provide evidence that CD4mc can efficiently sensitize primary CD4 T cells from HIV-1-infected individuals to ADCC mediated by autologous sera and effector cells. Therefore, CD4mc might represent an attractive approach to prevent and control HIV-1 infection.
Neuronal thresholds and choice-related activity of otolith afferent fibers during heading perception
Authors: Yu Xiong-jie , Dickman J. David , DeAngelis Gregory C. , Angelaki Dora E.
Published: May 2015

Significance

One major goal of systems neuroscience over the past decades has been to understand how the activity of sensory neurons mediates perception in simple decision-making tasks. It has remained fundamentally unclear whether and how the activity of primary sensory afferents limits behavior and contributes to decisions. We have tackled these issues by recording, for the first time to our knowledge, from otolith afferents during a heading discrimination task. We show otolith afferents have sensitivity comparable to central neurons, with some approaching behavior. However, they do not exhibit significant choice-related activity, indicating that downstream transformations of vestibular signals are necessary for vestibular activity to become predictive of the animal’s choices. These findings have important implications for understanding how choice-related activity arises in sensory pathways.
Overview.
Authors: Prasad C. S. , Malik P. K. , Bhatta R.
Published: May 2015

This chapter discussed briefly the current economic status and trends with regards to livestock production and highlights the inter-dependence of livestock production and climate change as well as the impact of climate change to the livestock sector.
Strategies for alleviating abiotic stress in livestock.
Authors: Sejian V. , Iqbal Hyder Iqbal Hyder , Malik P. K. , Soren N. M. , Mech A. , Mishra A. , Ravindra J. P.
Published: May 2015

The livestock sector accounts for 40% of the world's agriculture gross domestic product (GDP). It employs 1.3 billion people and creates livelihoods for 1 billion of the population living in poverty. Climate change is seen as a major threat to the survival of many species and ecosystems, and the sustainability of livestock production systems in many parts of the world. On the one hand, the current trend for the demand of livestock products is increasing, which offers market opportunities for small, marginal and landless farmers, while on the other hand, livestock production is facing the negative implications of environmental change, where abiotic stress is noteworthy. For animals, heat stress is the most stressful among all the abiotic stressors. Reducing the impact of abiotic stress on livestock requires a multidisciplinary approach with emphasis on nutrition, housing and health. Some biotechnological options may also be used to reduce abiotic stress. It is important to understand the livestock responses to environment and to analyse them carefully in order to alter nutritional and environment-related management practices. Future research needs for ameliorating abiotic stress in livestock are to identify strategies for developing and monitoring appropriate measures of heat stress; to assess the genetic components, including the genomics and proteomics of heat stress in livestock; and to develop alternative management practices for reducing abiotic stress and improving animal well-being and performance.
Nutritional strategies for minimizing phosphorus pollution from the livestock industry.
Authors: Ray P. P. , Knowlton K. F.
Published: May 2015

Livestock manure traditionally has been considered and used as a valuable resource by farmers to improve crop production. Livestock manure is rich in nutrients (nitrogen (N) and phosphorus (P)) and thus has been land applied to enrich soils. But land application of manure nutrients in excess of crop requirements can lead to saturated soil and loss of nutrients to surface water via runoff. Environmental concerns with P from animal agriculture are significant because livestock manure has always been land applied to meet crops' N requirement, resulting in P application in excess of crops' P requirement. The problem is aggravated with the intensification of livestock production, and now animal agriculture has been identified as a primary source of water quality impairment in many regions. But intensification and continuous advancement of livestock production is required to meet the increasing demand of food supply to feed a growing global population. Therefore, management strategies are needed that will improve livestock production while supporting the environmental and social pillars of sustainability. Nutritional strategies are economically and environ mentally efficient tools to reduce P excretion by livestock. This chapter discusses nutritional strategies including precision feeding, phase feeding and approaches to improve feed P availability.
Metagenomic approaches in harnessing gut microbial diversity.
Authors: Thulasi A. , Lyju Jose Lyju Jose , Chandrasekharaiah M. , Rajendran D. , Prasad C. S.
Published: May 2015

The mechanisms involved in the digestive process of the rumen are complex, and are accomplished by a diverse and dynamic group of microbes. Microbial diversity in the rumen has been predicted to enhance the resistance of the network of metabolic pathways by increasing the number of genes encoding the pathway, enabling the ecosystem to stabilize more rapidly after change to a new equilibrium. The more resistant metabolic pathways, and the more diverse source of novel pathways, will make the microbial system more resilient. A variety of molecular methods based on direct isolation and analysis of nucleic acids, proteins and lipids from environmental samples have been discovered, and they reveal structural and functional information about microbial communities. Molecular approaches such as genetic fingerprinting, metagenomics, meta proteomics, metatranscriptomics and proteogenomics are vital for discovering and characterizing the vast diversity of microbes and understanding their interactions with biotic and abiotic environmental factors. In this chapter, efforts are made to discover the possible applications of metagenomic tools for exploring the complex microbial diversity of ruminal microbes.
Perspective on livestock-generated GHGs and climate.
Authors: Takahashi J.
Published: May 2015

The greenhouse gases (GHGs) attributed to agriculture and animal agriculture are methane (CH4) and nitrous oxide (N2O). The relative absorptivity of the infrared radiation of carbon dioxide (CO2) is about 21-fold and 310-fold higher than for each molecule of CH4 or N2O, respectively. As the absorptivity in both gases is not saturated like CO2, the contribution of CH4 and N2O to the greenhouse effect have therefore been prospectively increasing linearly, because atmospheric increases in the concentration of both gases correlate closely with human activities, and the world population is currently expanding to more than 7 billion. Rumen CH4 production emitted to the atmosphere can be accounted as the biggest anthropogenic source. The abatement mechanism of rumen CH4 emission may be divided into direct and indirect suppression of methanogens in the rumen. The most significant strategy to mitigate rumen CH4 emission in an indirect manner is to promote alternative metabolic pathways to dispose of the reducing power, competing with methanogenesis for H2 uptake. In an attempt to identify natural manipulators with the efficacy to mitigate rumen CH4 emission, efficient prebiotics and probiotics have been developed in various institutions instead of ionophores in respect to food safety. The relatively lower molecular weight compounds produced by Lactobacillus plantarum have recently revealed the ability to suppress rumen methanogenesis. Some tropical and subtropical legume trees fed to cattle and buffalo as a protein source, due to their high protein content, are rich in secondary metabolites such as saponin and tannin, which is a type of polyphenol, etc. Some of them have been reported to abate rumen CH4 production remarkably well in vitro or in vivo. In some cases, however, experimental results are in agreement but may not match. Meta-analysis might be useful to integrate statistically the experimental results from independent studies for comprehensive understanding in the next stage of research. Although the inventory assessment of N2O is still ongoing, animal manures, including those from monogastrics, have been listed as a significant contributor. The incomprehensible fates of organic and inorganic nitrogen compounds contained in the aerobic composting of animal manures may confuse an accurate evaluation of the actual emission of N2O from animal manures. Of late, there has been an urgent need for renewable energy production using anaerobic digesters to capture biogas (CH4) from animal effluent. Most manure nitrogen during fermentation has been converted to an inorganic form in the digested slurry.
Carbon footprints of food of animal origin.
Authors: Flachowsky G.
Published: May 2015

Animal production contributes substantially to global greenhouse gas emissions (about 14.5%). So-called carbon footprints (CFs) consider the greenhouse gas potential of climate-relevant gases (e.g. CO2 × 1; CH4 × 23; N2O × 296), which is given in carbon dioxide (CO2)-equivalent g-1 or kg-1 of product or unit of edible protein. CFs may help to assess the greenhouse gas emissions associated with the production of food of animal origin such as milk, meat, eggs or fish, and they may contribute to sensitizing producers and consumers to a more resource-efficient and environmentally friendly production and consumption of food of animal origin and to avoiding food wastage. The highest CFs per unit edible protein are calculated for products of growing ruminants (beef and lamb), followed by milk, pork, eggs and poultry meat, with the lowest values. Discrepancies in the results of various studies are explained mainly by different system boundaries, allocation methods and computation of emissions, especially with regard to land-use changes, enteric methane (CH4) and nitrous oxide (N2O) emissions. A more standardized approach for CF calculations would be a very useful tool to compare CFs between production systems, regions and countries, and as an indicator for food labelling. The production of food of animal origin is a very complex process, and a selective consideration, i.e. focusing on single factors, does not provide an assessment that reflects the complexity of the subject.
Climate change: impacts on livestock diversity in tropical countries.
Authors: Banik S. , Pankaj P. K. , Naskar S.
Published: May 2015

The effect of changing climate will not only be confined to limited production, and the productivity of agricultural commodities, but will also have far-reaching consequences on dairy, meat, wool and other animal products. The impact of climate change on the livestock sector as a whole will be felt more in tropical countries compared to temperate countries, largely because of the structure of production system and economics. The resultant pressure, both direct and indirect, is likely to result in further dilution of livestock diversity, which would specially affect the nutritional security and livelihood of small and marginal farmers. The challenge is to sustain genetic diversity and productivity by different adaptation strategies like production adjustment, breeding strategies, alteration of management systems, developing appropriate policies, scientific intervention and capacity building of livestock owners. In light of concerns over the impacts of climate change and climate variability, this chapter provides an overview of the opportunities for adaptation and mitigation strategies in tropical climatic conditions.
Climate change: impact of meat production.
Authors: Musalia L. M.
Published: May 2015

Between 1961 and 2009, the world recorded a continued increase in the demand for meat, driven by the fast growth in population, economic improvement, changes in eating habits and rapid urbanization. This has resulted in improved livestock production that is projected to continue even into the future. However, raising animals for food has been identified as a major contributor to climate change. As more meat is produced to satisfy the increasing demand, it is important to understand its effect on climate change, which continues to be a threat to food security. Livestock production contributes 14.5% of the total greenhouse gases (GHGs) that originate directly from the animal in the form of enteric emissions (39%), or indirectly from activities in the meat production value chain like animal feed production and processing (45%), manure decomposition (10%) and slaughter, processing and transportation of animal products (6%). The amount of GHGs emitted in meat production depends on the type of feed and the capability of the animals to digest and utilize feeds, thus minimizing the amount of waste excreted. The production of meat is a very inefficient system where animal proteins require 11 times more fossil fuel compared to plant protein. The efficiency of meat production reduces in the order of fish, poultry, pork and beef. Efficient meat production systems also cut down on the emissions associated with the production of massive feeds. Meat production systems involving ruminant animals and feeding fibrous or poor-quality feeds contribute significantly to enteric emission and manure production, and the inefficiency of feed utilization and meat from these systems has a high GHG effect.
Enteric methane emission: status, mitigation and future challenges - an Indian perspective.
Authors: Raghavendra Bhatta Raghavendra Bhatta , Malik P. K. , Prasad C. S.
Published: May 2015

1% per annum. To stabilize this greenhouse gas in the atmosphere, global CH4 production needs to be reduced by 10-20%. Ruminants fed on low-quality feed/fodder produce over 75% of the CH4 generated by ruminants worldwide. Strategic supplementation to improve digestive efficiency in these animals could halve this CH4 production per unit of feed consumed. Supplementation to improve the efficiency of feed utilization coupled with increased product output may thus reduce CH4 production per unit of milk or meat by a factor of 4-6. The dietary/nutritional strategy that improves productivity with no potential negative effects on livestock health and production is cost-effective and has a better chance of being adopted. Other strategies (biotechnologies, additives) are promising, but the diversity and plasticity of the functions of the rumen bacterial and methanogenic communities may be the limiting factor for their successful application. In addition, the environmental impacts of strategies should also be taken into consideration. A global vision of production systems that considers all greenhouse gas emissions from the animal up to the farm scale, as well as grassland use, is essential. Further, the sustainability of CH4-suppressing strategies is an important issue. An effort is made in this chapter to address enteric CH4 emissions and their current status. An overview on the possible ameliorative strategies has also been given.
Ionophores: a tool for improving ruminant production and reducing environmental impact.
Authors: Bell N. , Wickersham T. , Sharma V. , Callaway T.
Published: May 2015

Ruminal fermentation is an inherently inefficient process converting up to 12% of dietary carbon and energy into end products (e.g. CH4) that are largely unusable by the animal. Ruminant nutritionists seek to modify fermentation, specifically by increasing ruminal propionic acid yield, reducing methanogenesis and decreasing ruminal proteolysis and deamination of dietary proteins in order to improve production efficiency. To date, a variety of methods have been investigated in an effort to meet these objectives. Carboxylic polyether compounds, 'ionophores', are an effective means of decreasing enteric CH4 emissions when included in ruminant diets. Although ruminant nutritionists have historically focused on feeding ionophores to increase efficiency and profitability, recent attention has focused on the ability of ionophores to impact global greenhouse gas production. This chapter examines the use of ionophores in cattle diets for the mitigation of enteric CH4 production. Issues like ionophore resistance and the impact of ionophore feeding on human health are also addressed.
Acetogenesis as an alternative to methanogenesis in the rumen.
Authors: Gagen E. J. , Denman S. E. , McSweeney C. S.
Published: May 2015

Bacteria capable of producing acetate from H2 and CO2 using the acetyl-CoA pathway (4H2+2CO2 → CH3COOH+2H2O) are known as acetogens. They have been found in a variety of anaerobic ecosystems, including sediments, wastewater treatment systems, soils and animal gut systems. In recent years, acetogens have received attention as a hydrogenotrophic population that may play a role in reducing methane (CH4) emissions from ruminant animals. During ruminal fermentation, methanogenic archaea reduce CO2 (4H2+CO2 → CH4+2H2O) or methylated compounds to CH4. Ruminal methanogenesis represents a loss of 2-12% of gross energy of ingested feed and contributes significantly to global greenhouse gas emissions. If methanogenesis could be suppressed in the rumen, acetogenesis may serve as an effective alternative hydrogen sink, resulting in an energy gain for the ruminant through the production of acetate. Acetogenesis is the dominating hydrogenotrophic pathway in other gut systems such as those of humans, pigs, termites and potentially some native Australian marsupials. The latter are of particular interest as they exhibit foregut fermentation analogous to that of ruminants, though resulting in significantly less CH4 production, suggesting the functioning of alternative hydrogen sinks to methanogenesis. Recent molecular investigations of the bovine and ovine rumen and the tammar wallaby forestomach revealed the presence of a diversity of functional gene sequences associated with reductive acetogenesis that demonstrate only low similarity to sequences from presently isolated authentic rumen acetogens. Giving the natural rumen acetogen population a competitive advantage over methanogens may be a strategy for establishing reductive acetogenesis rather than methanogenesis as the major hydrogen sink in the rumen. Methanogen inhibitors may aid this process, allowing hydrogen in the rumen to accumulate to levels where it can be utilized by acetogens. Previous researchers have found that reductive acetogenesis was enhanced in the presence of methanogen inhibitors in ruminal incubations. Also, acetogen enhancers may provide acetogens with an advantage over methanogens in the rumen. Continued study into the factors affecting ruminal acetogens and their interactions with methanogens is certainly needed.
Immunization and tannins in livestock enteric methane amelioration.
Authors: Uyeno Y.
Published: May 2015

The complexity of the rumen microbial ecosystem supports the efficient conversion of various carbohydrates to volatile fatty acids for fulfilling host energy requirement via stepwise disposal of hydrogen (H2) through the reduction of carbon dioxide (CO2) to methane (CH4). Although, this mechanism is indispensable for rumen homeostasis, CH4 production in ruminants has attracted a great deal of attention due to its contribution to the greenhouse gas effect and global warming. Various strategies have therefore been considered for its mitigation. Rumen methanogen targeting vaccination is a promising means of reducing CH4 emissions by decreasing the number or activity of rumen methanogens. However, trials of this strategy have provided inconsistent results, and need for further consideration of the composition, function and microbial interactions within the ecosystem. Alternatively, to establish a more efficient way for the mitigation of CH4 emission, systematic intervention in rumen microbial populations by a combination of vaccination and other chemical means may also be feasible. Although some of the CH4 abatement strategies have shown efficacy in vivo, more research is needed to make any of these approaches applicable to animal production systems. This chapter provides the background to the diversity and plasticity of functions of the rumen bacterial and methanogenic communities, as well as some of the CH4 abatement options that aim to manipulate the rumen community, including immunization and other concepts.
Phage therapy in livestock methane amelioration.
Authors: Gilbert R. A. , Ouwerkerk D. , Klieve A. V.
Published: May 2015

Viruses of prokaryotes (phages) are obligate microbial pathogens that can, in the lytic phase of development, infect and lyse their respective bacterial or archaeal hosts. As such, these viruses can reduce the population density of their hosts rapidly, and have been viewed as possible agents of biological control (phage therapy). Phage therapy is becoming increasingly important as a means of eradicating or controlling microbial populations as the use of antibiotics and chemical treatments becomes both less effective and less publicly acceptable. Phage therapy has therefore been raised as a potential strategy to reduce methane (CH4) emissions from ruminants, providing an innovative biological approach, harnessing the potent, yet targeted, biocidal attributes of these naturally occurring microbial predators.
Summary.
Authors: Malik P. K. , Bhatta R. , Saravanan M. , Baruah L.
Published: May 2015

This chapter summarizes the full content of this book where contributors have addressed various aspects of livestock production vis-à-vis climate change. Improving livestock production and productivity is the need of the hour to accomplish the ever increasing demand of the populace. Climate change appears to be a major constraint in this endeavour as it severely affects livestock directly or indirectly. Further, livestock itself is accountable for the climatic variations and negative environmental complications of climate change by dispensing large quantities of greenhouse gases into the atmosphere. The implications of climate change on livestock, the involvement of livestock in climate change, mitigation approaches and adaptation strategies for minimizing the adverse impact and reducing enteric methane (CH4) emissions debated in the various chapters of this book are summarized here.
Status of resistance to Bt cotton in China: cotton bollworm and pink bollworm.
Authors: Gao YuLin Gao YuLin , Liu ChenXi Liu ChenXi , Wu YiDong Wu YiDong , Wu KongMing Wu KongMing
Published: May 2015

Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating the cotton pests Helicoverpa armigera and Pectinophora gossypiella since 1997 in China. The pest management tactics associated with Bt cotton have resulted in a drastic reduction in insecticide use. However, the evolution of resistance by the pests threatens the continued success of Bt cotton. The development of resistance to Bt is of great concern, and there is a vast body of research in this area aimed at ensuring the continued success of Bt cotton. Here, we review studies on the evolution of Bt resistance in these two bollworms, focusing on the commercial release of Bt cotton varieties in China, and the biochemical and molecular basis of Bt resistance. We also discuss resistance management strategies, and monitoring programmes implemented in China and other countries.
Resistance of Busseola fusca to Cry1Ab Bt maize plants in South Africa and challenges to insect resistance management in Africa.
Authors: Berg J. van den , Campagne P.
Published: May 2015

The evolution of resistance to Bacillus thuringiensis (Bt) maize by the African stem borer, Busseola fusca, in South Africa highlighted the importance of the development of appropriate integrated resistance management (IRM) strategies for stem borers in Africa. Landscape heterogeneity is characteristic of African agroecosystems. This heterogeneity, in addition to between field and within-field spatial mosaics resulting from variable gene expression in Bt maize, will provide challenges to managing resistance evolution of the lepidopteran stem borers that attack maize. Adding to this landscape heterogeneity is the cultivation of open-pollinated maize varieties (OPVs) and bimodal rainfall patterns that allow two maize cropping seasons each year in many subtropical and tropical areas. The role that these factors, as well as aspects such as low-dose expression events, refuge compliance, the genetic bases of resistance, pest behaviour, host plant range and farming practices, may play in the evolution of stem borers to Bt maize in Africa are addressed in this chapter.
Roles of insect midgut cadherin in Bt intoxication and resistance.
Authors: Fabrick J. A. , Wu YiDong Wu YiDong
Published: May 2015

Genetically engineered crops producing Bacillus thuringiensis (Bt) proteins for insect control target major insect pests. Bt crops have improved yields and their use reduces the risks associated with the application of conventional insecticides. However, the evolution of resistance to Bt toxins by target pests threatens the long-term success of such transgenic crops. Insects resistant to Bt Cry toxins have been selected in the laboratory and field-evolved resistance has been reported for economically important insects in several regions of the world. Although the mechanisms of resistance have not been reported for all cases, the most common mechanism involves changes in larval midgut target sites that probably reduce binding to Bt toxins. The binding of Cry toxins to midgut cadherin represents an important step in Bt intoxication for many insects and mutations in the cadherin gene can result in resistance to Bt toxins. Here, we highlight the roles that insect midgut cadherins play in Bt Cry intoxication and review cases where changes in cadherin are involved with resistance to Cry toxins. Furthermore, we emphasize the importance of understanding the underlying molecular basis of Bt intoxication and resistance to Bt, and the implications of fundamental knowledge for resistance management strategies.
The role of proteolysis in the biological activity of Bt insecticidal crystal proteins.
Authors: Zalunin I. A. , Elpidina E. N. , Oppert B.
Published: May 2015

The crystal toxins (Cry) produced by the bacterium Bacillus thuringiensis (Bt) have been successfully used in both spray formulations and transgenic crops to control some of the most problematic insect pests, as has been discussed in previous chapters. The δ-endotoxins of Bt are functionally active in the insect gut and interact with and are processed by proteolytic enzymes. The structure of Cry proteins has specific features that not only permit them to retain their biological activity in the hostile environment of the insect gut, but also to use the process of proteolysis in the solubilization and activation of Cry protoxins. Because the proteolysis of Cry proteins is critical to their biological activity, we review the literature on studies related to insect and mammalian proteases and their effects on toxin structure and toxicity.
The development and prospect of discovery of Bt toxin genes.
Authors: Zhang Jie Zhang Jie , Shu ChangLong Shu ChangLong , Wang ZeYu Wang ZeYu
Published: May 2015

Bacillus thuringiensis (Bt) Cry protein-based insect control has proven to be effective in reducing the use of chemical insecticides and in increasing crop yields. However, Bt crops increase selection pressure for resistant insects and accelerate their succession. The discovery and application of different Bt toxins that have no cross-resistance with known toxins has been proposed as a strategy for the management of resistant insects. Additionally, the discovery of novel Bt toxins with a new insecticidal spectrum will control insect succession. In fact, the discovery of new Bt toxins is one of the most important areas in Bt research, and the most advanced molecular biology methods available have been applied to this task. In this chapter, we summarize the published methods for Bt toxin discovery.
RNA interference strategy for crop protection against insect pests.
Authors: Sneha Yogindran Sneha Yogindran , Rajam M. V.
Published: May 2015

RNA interference (RNAi) has significantly accelerated functional genomic research on insects. Since its discovery, numerous reports have reported efforts to apply RNAi approaches to insect species lacking characterized genomes. The technique also has substantial potential for use in the control of insect pests that cause severe loss of crop yield and quality. Several approaches have been exploited to control these pests, including the application of different agrochemicals and the development of resistant crops by breeding and transgenic approaches. However, there are certain limitations with these strategies, and therefore novel alternative strategies are required for the development of stress-tolerant plants. RNAi strategies have proven to be such a novel and potential alternative for disease and pest control. This technique essentially involves the production of hairpin double-stranded RNA (dsRNA) in transgenic plants that targets pest genes that are essential for their growth and development. This chapter provides an insight into the practical aspects of this gene silencing methodology for the development of tools for pest management.
Rab27a controls HIV-1 assembly by regulating plasma membrane levels of phosphatidylinositol 4,5-bisphosphate
Authors: Gerber Pehuén Pereyra , Cabrini Mercedes , Jancic Carolina , Paoletti Luciana , Banchio Claudia , von Bilderling Catalina , Sigaut Lorena , Pietrasanta Lía I. , Duette Gabriel , Freed Eric O. , de Saint Basile Genevieve , Moita Catarina Ferreira , Moita Luis Ferreira , Amigorena Sebastian , Benaroch Philippe , Geffner Jorge , Ostrowski Matías
Published: May 2015

During the late stages of the HIV-1 replication cycle, the viral polyprotein Pr55Gag is recruited to the plasma membrane (PM), where it binds phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and directs HIV-1 assembly. We show that Rab27a controls the trafficking of late endosomes carrying phosphatidylinositol 4-kinase type 2 α (PI4KIIα) toward the PM of CD4+ T cells. Hence, Rab27a promotes high levels of PM phosphatidylinositol 4-phosphate and the localized production of PI(4,5)P2, therefore controlling Pr55Gag membrane association. Rab27a also controls PI(4,5)P2 levels at the virus-containing compartments of macrophages. By screening Rab27a effectors, we identified that Slp2a, Slp3, and Slac2b are required for the association of Pr55Gag with the PM and that Slp2a cooperates with Rab27a in the recruitment of PI4KIIα to the PM. We conclude that by directing the trafficking of PI4KIIα-positive endosomes toward the PM, Rab27a controls PI(4,5)P2 production and, consequently, HIV-1 replication.
Hsp72 is targeted to the mitotic spindle by Nek6 to promote K-fiber assembly and mitotic progression
Authors: O’Regan Laura , Sampson Josephina , Richards Mark W. , Knebel Axel , Roth Daniel , Hood Fiona E. , Straube Anne , Royle Stephen J. , Bayliss Richard , Fry Andrew M.
Published: May 2015

Hsp70 proteins represent a family of chaperones that regulate cellular homeostasis and are required for cancer cell survival. However, their function and regulation in mitosis remain unknown. In this paper, we show that the major inducible cytoplasmic Hsp70 isoform, Hsp72, is required for assembly of a robust bipolar spindle capable of efficient chromosome congression. Mechanistically, Hsp72 associates with the K-fiber–stabilizing proteins, ch-TOG and TACC3, and promotes their interaction with each other and recruitment to spindle microtubules (MTs). Targeting of Hsp72 to the mitotic spindle is dependent on phosphorylation at Thr-66 within its nucleotide-binding domain by the Nek6 kinase. Phosphorylated Hsp72 concentrates on spindle poles and sites of MT–kinetochore attachment. A phosphomimetic Hsp72 mutant rescued defects in K-fiber assembly, ch-TOG/TACC3 recruitment and mitotic progression that also resulted from Nek6 depletion. We therefore propose that Nek6 facilitates association of Hsp72 with the mitotic spindle, where it promotes stable K-fiber assembly through recruitment of the ch-TOG–TACC3 complex.
Head-to-tail regulation is critical for the in vivo function of myosin V
Authors: Donovan Kirk W. , Bretscher Anthony
Published: May 2015

Cell organization requires regulated cargo transport along cytoskeletal elements. Myosin V motors are among the most conserved organelle motors and have been well characterized in both yeast and mammalian systems. Biochemical data for mammalian myosin V suggest that a head-to-tail autoinhibitory interaction is a primary means of regulation, but the in vivo significance of this interaction has not been studied. Here we generated and characterized mutations in the yeast myosin V Myo2p to reveal that it is regulated by a head-to-tail interaction and that loss of regulation renders the myosin V constitutively active. We show that an unregulated motor is very deleterious for growth, resulting in severe defects in Myo2-mediated transport processes, including secretory vesicle transport, mitochondrial inheritance, and nuclear orientation. All of the defects associated with motor misregulation could be rescued by artificially restoring regulation. Thus, spatial and temporal regulation of myosin V in vivo by a head-to-tail interaction is critical for the normal delivery functions of the motor.
Replication of Plasmodium in reticulocytes can occur without hemozoin formation, resulting in chloroquine resistance
Authors: Lin Jing-wen , Spaccapelo Roberta , Schwarzer Evelin , Sajid Mohammed , Annoura Takeshi , Deroost Katrien , Ravelli Raimond B.G. , Aime Elena , Capuccini Barbara , Mommaas-Kienhuis Anna M. , O’Toole Tom , Prins Frans , Franke-Fayard Blandine M.D. , Ramesar Jai , Chevalley-Maurel Séverine , Kroeze Hans , Koster Abraham J. , Tanke Hans J. , Crisanti Andrea , Langhorne Jean , Arese Paolo , Van den Steen Philippe E. , Janse Chris J. , Khan Shahid M.
Published: May 2015

Most studies on malaria-parasite digestion of hemoglobin (Hb) have been performed using P. falciparum maintained in mature erythrocytes, in vitro. In this study, we examine Plasmodium Hb degradation in vivo in mice, using the parasite P. berghei, and show that it is possible to create mutant parasites lacking enzymes involved in the initial steps of Hb proteolysis. These mutants only complete development in reticulocytes and mature into both schizonts and gametocytes. Hb degradation is severely impaired and large amounts of undigested Hb remains in the reticulocyte cytoplasm and in vesicles in the parasite. The mutants produce little or no hemozoin (Hz), the detoxification by-product of Hb degradation. Further, they are resistant to chloroquine, an antimalarial drug that interferes with Hz formation, but their sensitivity to artesunate, also thought to be dependent on Hb degradation, is retained. Survival in reticulocytes with reduced or absent Hb digestion may imply a novel mechanism of drug resistance. These findings have implications for drug development against human-malaria parasites, such as P. vivax and P. ovale, which develop inside reticulocytes.
Growth
Authors: Bénassy Jean-Pascal
Published: May 2015

This chapter commences with the so-called exogenous growth models. It describes the most classic model of the domain, the Solow-Swan model, which explains principally increases in national production by factor accumulation. Also, it presents the short-run equilibrium and the dynamics of Slow-Swan model, and sets forth the exogenous technical progress. The chapter then examines the problem of convergence across different economies, and illustrates a model having two accumulated factors: physical capital and human capital.
Output, Inflation, and Stabilization
Authors: Bénassy Jean-Pascal
Published: May 2015

This chapter describes a number of historical models, particularly the most traditional Keynesian models, such as the Keynesian cross, the IS-LM model, and the AD-AS model. These models are primarily static and based on temporary price and wage rigidities. The chapter then examines the Phillips curve, which describes the evolution of wages in response to unemployment. It discusses how the interaction of the Phillips curve and the evolution of expectations determines the joint dynamics of inflation and unemployment. It also illustrates the eminent debate on stabilization in the Keynesian mode.