Exceptional sperm cooperation in the wood mouse

Spermatozoa from a single male will compete for fertilization of ova with spermatozoa from another male when present in the female reproductive tract at the same time. Close genetic relatedness predisposes individuals towards altruism, and as haploid germ cells of an ejaculate will have genotypic similarity of 50%, it is predicted that spermatozoa may display cooperation and altruism to gain an advantage when inter-male sperm competition is intense. We report here the probable altruistic behaviour of spermatozoa in an eutherian mammal. Spermatozoa of the common wood mouse, Apodemus sylvaticus, displayed a unique morphological transformation resulting in cooperation in distinctive aggregations or 'trains' of hundreds or thousands of cells, which significantly increased sperm progressive motility. Eventual dispersal of sperm trains was associated with most of the spermatozoa undergoing a premature acrosome reaction. Cells undergoing an acrosome reaction in aggregations remote from the egg are altruistic in that they help sperm transport to the egg but compromise their own fertilizing ability

BIOMASS QUANTIFICATION IN A SEASONAL DECIDUOUS FOREST IN ITAARA, RS, BRAZIL

O presente trabalho foi realizado no munic\uedpio de Itaara, RS, Brasil, em uma Floresta Estacional Decidual secund\ue1ria com 70 anos aproximadamente. O estudo teve como principal objetivo quantificar a biomassa acima do solo na floresta. Para tanto, foram abatidas vinte \ue1rvores distribu\ueddas em cinco classes de di\ue2metros. As \ue1rvores abatidas foram separadas nas fra\ue7\uf5es, madeira do fuste, casca do fuste, galhos e folhas. Em cada fra\ue7\ue3o, foram retiradas amostras para determina\ue7\ue3o da umidade, determinado o peso seco de cada componente. A estimativa da biomassa foi obtida pelo uso da equa\ue7\ue3o log y = b0 + b1 . log DAP. A produ\ue7\ue3o total estimada de biomassa acima do solo foi de 210,0 Mg ha-1. Nessa estimativa, os galhos corresponderam a 48,8%, a madeira do fuste 43,3%, a casca do fuste 5,4%, e as folhas 2,4%.This work was carried out in the city of Itaara-RS, Brazil. The present work has as main objective the quantification of the above ground biomass. To do so, it had been cut down 20 trees and they were distributed in 5 different diameter classes. The trees had been separated in the components stem timber, stem bark, branches and leaves. In each fraction, samples for determination of humidity had been removed, of each component determined the dry weight. The estimate of the biomass was done by the use of the equation log y = b0 + b1 . log DAP. The total production of above ground biomass was 210,0 Mg ha-1. In this estimate, the branches had corresponded to 48,8% of the above ground biomass, followed by the shafts wood with 43,3%, bark with 5,4% and the leaves with 2,4%

ESTIMATE OF LITTER FALL IN SEASONAL DECIDUOUS FOREST IN ITAARA, RS, BRAZIL

O presente trabalho foi realizado na fazenda da Brigada Militar no munic\uedpio de Itaara, RS, Brasil, e teve como principal objetivo avaliar a devolu\ue7\ue3o de serapilheira em uma Floresta Estacional Decidual. Para a coleta de serapilheira, foram demarcadas seis parcelas de 25 m x 17 m cada, alocadas no interior da floresta. Em cada parcela, foram distribu\ueddos cinco coletores, totalizando 30 coletores, constitu\ueddos por uma moldura de ferro de forma circular, com 50 cm de di\ue2metro. As coletas de serapilheira foram realizadas mensalmente, durante um per\uedodo de 2 anos. No laborat\uf3rio, o material foi separado nas fra\ue7\uf5es folhas, galhos finos (< 1 cm) e miscel\ue2nea (flores, frutos, sementes e restos vegetais n\ue3o-identific\ue1veis). Nos dois anos de coleta, houve grande devolu\ue7\ue3o de serapilheira no in\uedcio do inverno e principalmente na primavera, aumentando nos meses de setembro e novembro, no primeiro ano. No segundo ano, apesar da menor devolu\ue7\ue3o mensal, essa tend\ueancia manteve-se mais ou menos constante, indicando um padr\ue3o sazonal nessa floresta. A devolu\ue7\ue3o m\ue9dia anual de serapilheira foi de 7436,0 kg ha-1, com uma distribui\ue7\ue3o relativa de 71,7% de folhas, 16,5% de galhos finos e 11,8% de miscel\ue2nea. N\ue3o foi verificada uma correla\ue7\ue3o significativa entre as vari\ue1veis clim\ue1ticas precipita\ue7\ue3o e temperatura e a devolu\ue7\ue3o de serapilheira.This work was carried out in the farm of the Military Brigade in the city of Itaara, RS, Brazil. The present work has as main objective to evaluate the estimate of litter fall in Seasonal Deciduous Forest. For the litter collection, six plots of 25 m x 17 m had been demarcated, placed in the forest. In each plot, five litter traps had been distributed, totalizing 30 traps. The litter collections had been carried out monthly, during a period of 2 years (December of 2002 to November of 2004). In the laboratory, the material was separated in fractions, leaves, small twigs and miscellaneous (flowers, fruits, seeds and residues not identified). During the two years of collection, it could be observed great litter deposition in the in the beginning of the winter and mainly in the spring with the biggest depositions during September and November, indicating a standard seasonal in this forest. The leaves had been responsible for 71.3% of the composition of the litter, the fine twigs had contributed with 16.7%, and the miscellany with the lesser ratio of 12.1%, in the two years of collection. A significant correlation between the litter deposition and the climatic variables was not verified

Effect Threshold for Selenium Toxicity in Juvenile Splittail, Pogonichthys macrolepidotus A

In fish, selenium can bioaccumulate and cause adverse impacts. One of the fish species potentially at risk from selenium in the San Francisco Bay (California, USA) is the splittail (Pogonichthys macrolepidotus). Previous studies have derived a whole body NOAEL and LOAEL of 9.0 and 12.9 mg/kg-dw, respectively, for selenium in juveniles. However, the NOAEL/LOAEL approach leaves some uncertainty regarding the threshold of toxicity. Therefore, the raw data from the original experiment was re-analyzed using a logistic regression to derive EC10 values of 0.9 mg/kg-dw in feed, 7.9 mg/kg-dw in muscle, 18.6 mg/kg-dw in liver for juvenile splittail. Selenium concentrations in the dietary items of wild splittail exceed the EC10 values derived here. Thus, deformities previously reported in wild splittail may have resulted from selenium exposures via the food chain

Eliciting the Impact of Digital Consulting for Young People Living With Long-term Conditions (Lync Study): Cognitive Interviews to Assess the Face and Content Validity of Two Patient-Reported Outcome Measures

BACKGROUND: Digital consulting, using email, text, and Skype, is increasingly offered to young people accessing specialist care for long-term conditions. No patient-reported outcome measures (PROMs) have been evaluated for assessing outcomes of digital consulting. Systematic and scoping reviews, alongside patient involvement, revealed 2 candidate PROMs for this purpose: the patient activation measure (PAM) and the physician’s humanistic behaviors questionnaire (PHBQ). PAM measures knowledge, beliefs, and skills that enable people to manage their long-term conditions. PHBQ assesses the presence of behaviors that are important to patients in their physician-patient interactions. OBJECTIVE: This study aimed to assess the face and content validity of PAM and PHBQ to explore whether they elicit important outcomes of digital consulting and whether the PROMs can isolate the digital consultation component of care. METHODS: Participants were drawn from 5 clinics providing specialist National Health Service care to 16- to 24-year-olds with long-term health conditions participating in the wider LYNC (Long-Term Conditions, Young People, Networked Communications) study. Overall, 14 people undertook a cognitive interview in this substudy. Of these, 7 participants were young people with either inflammatory bowel disease, cystic fibrosis, or cancer. The remaining 7 participants were clinicians who were convenience sampled. These included a clinical psychologist, 2 nurses, 3 consultant physicians, and a community youth worker practicing in cancer, diabetes, cystic fibrosis, and liver disease. Cognitive interviews were transcribed and analyzed, and a spreadsheet recorded the participants’ PROM item appraisals. Illustrative quotes were extracted verbatim from the interviews for all participants. RESULTS: Young people found 11 of the PAM 13 items and 7 of the additional 8 PAM 22 items to be relevant to digital consulting. They were only able to provide spontaneous examples of digital consulting for 50% (11/22) of the items. Of the 7 clinicians, 4 appraised all PAM 13 items and 20 of the PAM 22 items to be relevant to evaluating digital consulting and articulated operationalization of the items with reference to their own digital consulting practice with greater ease than the young people. Appraising the PHBQ, in 14 of the 25 items, two-thirds of the young people’s appraisals offered digital consulting examples with ease, suggesting that young people can detect and discern humanistic clinician behaviors via digital as well as face-to-face communication channels. Moreover, 17 of the 25 items were appraised as relevant by the young people. This finding was mirrored in the clinician appraisals. Both young people and the clinicians found the research task complex. Young participants required considerably more researcher prompting to elicit examples related to digital consulting rather than their face-to-face care. CONCLUSIONS: PAM and PHBQ have satisfactory face and content validity for evaluating digital consulting to warrant proceeding to psychometric evaluation. Completion instructions require revision to differentiate between digital and face-to-face consultations

Dynamic localization of a helper NLR at the plant-pathogen interface underpins pathogen recognition

Plants employ sensor-helper pairs of NLR immune receptors to recognize pathogen effectors and activate immune responses (1). Yet the subcellular localization of NLRs pre- and post-activation during pathogen infection remains poorly understood. Here we show that NRC4, from the ‘NRC’ solanaceous helper NLR family (1), undergoes dynamic changes in subcellular localization by shuttling to and from the plant-pathogen haustorium interface established during infection by the Irish potato famine pathogen Phytophthora infestans. Specifically, prior to activation, NRC4 accumulates at the extra-haustorial membrane (EHM), presumably to mediate response to perihaustorial effectors, that are recognized by NRC4- dependent sensor NLRs. However not all NLRs accumulate at the EHM, as the closely related helper NRC2, and the distantly related ZAR1, did not accumulate at the EHM. NRC4 required an intact N-terminal coiled coil domain to accumulate at the EHM, whereas the functionally conserved MADA motif implicated in cell death activation and membrane insertion was dispensable for this process. Strikingly, a constitutively autoactive NRC4 mutant did not accumulate at the EHM and showed punctate distribution that mainly associated with the plasma membrane, suggesting that post-activation, NRC4 may undergo a conformation switch to form clusters that do not preferentially associate with the EHM. When NRC4 is activated by a sensor NLR during infection however, NRC4 forms puncta mainly at the EHM and to a lesser extent at the plasma membrane. We conclude that following activation at the EHM, NRC4 may spread to other cellular membranes from its primary site of activation to trigger immune responses

Socio-Economic Instability and the Scaling of Energy Use with Population Size

The size of the human population is relevant to the development of a sustainable world, yet the forces setting growth or declines in the human population are poorly understood. Generally, population growth rates depend on whether new individuals compete for the same energy (leading to Malthusian or density-dependent growth) or help to generate new energy (leading to exponential and super-exponential growth). It has been hypothesized that exponential and super-exponential growth in humans has resulted from carrying capacity, which is in part determined by energy availability, keeping pace with or exceeding the rate of population growth. We evaluated the relationship between energy use and population size for countries with long records of both and the world as a whole to assess whether energy yields are consistent with the idea of an increasing carrying capacity. We find that on average energy use has indeed kept pace with population size over long time periods. We also show, however, that the energy-population scaling exponent plummets during, and its temporal variability increases preceding, periods of social, political, technological, and environmental change. We suggest that efforts to increase the reliability of future energy yields may be essential for stabilizing both population growth and the global socio-economic system

The cost of promiscuity: sexual transmission of Nosema microsporidian parasites in polyandrous honey bees

Multiple mating (and insemination) by females with different males, polyandry, is widespread across animals, due to material and/or genetic benefits for females. It reaches particularly high levels in some social insects, in which queens can produce significantly fitter colonies by being polyandrous. It is therefore a paradox that two thirds of eusocial hymenopteran insects appear to be exclusively monandrous, in spite of the fitness benefits that polyandry could provide. One possible cost of polyandry could be sexually transmitted parasites, but evidence for these in social insects is extremely limited. Here we show that two different species of Nosema microsporidian parasites can transmit sexually in the honey bee Apis mellifera. Honey bee males that are infected by the parasite have Nosema spores in their semen, and queens artificially inseminated with either Nosema spores or the semen of Nosema-infected males became infected by the parasite. The emergent and more virulent N. ceranae achieved much higher rates of infection following insemination than did N. apis. The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects, indicating that STDs may represent a potential cost of polyandry in social insects

Cost-effectiveness of pregabalin versus venlafaxine in the treatment of generalized anxiety disorder: findings from a Spanish perspective

The objective of the present study was to describe a new model of the cost-effectiveness of treatment of generalized anxiety disorder (GAD) and its application to a comparison of pregabalin versus venlafaxine extended-release (XR) from a Spanish healthcare perspective. Microsimulation techniques, including Hamilton Anxiety Scale (HAM-A) score, number of weeks with minimal or no anxiety (HAM-A ≤ 9), and quality-adjusted life-years (QALYs), were used to predict treatment outcomes for patients with moderate-to-severe GAD who would be treated with pregabalin vs venlafaxine XR. Expected levels of healthcare utilization and unit cost of care are derived from Spanish published sources. We express cost-effectiveness alternatively in terms of incremental cost per additional week with minimal or no anxiety, and incremental cost per QALY gained [in 2007 Euros (€)]. Considering costs of drug treatment only, the incremental cost [mean (95% confidence interval)] of pregabalin (vs venlafaxine XR) would be €96 (€86, €107) per additional week with minimal or no anxiety, and €32,832 (€29,656, €36,308) per QALY gained. When other medical care costs are considered, cost-effectiveness ratios decline to €70 (€61, €80) per additional week with no or minimal anxiety, and €23,909 (€20,820, €27,006) per QALY gained. We conclude that, using a new microsimulation model of the treatment of GAD, pregabalin appears to be cost-effective vs venlafaxine XR in a Spanish healthcare setting