Monogamy in large bee societies: a stingless paradox

High genetic diversity is important for the functioning of large insect societies. Across the social Hymenoptera (ants, bees, and wasps), species with the largest colonies tend to have a high colony-level genetic diversity resulting from multiple queens (polygyny) or queens that mate with multiple males (polyandry). Here we studied the genetic structure of Trigona spinipes, a stingless bee species with colonies an order of magnitude larger than those of polyandrous honeybees. Genotypes of adult workers and pupae from 43 nests distributed across three Brazilian biomes showed that T. spinipes colonies are usually headed by one singly mated queen. Apart from revealing a notable exception from the general incidence of high genetic diversity in large insect societies, our results reinforce previous findings suggesting the absence of polyandry in stingless bees and provide evidence against the sperm limitation hypothesis for the evolution of polyandry. Stingless bee species with large colonies, such as T. spinipes, thus seem promising study models to unravel alternative mechanisms to increase genetic diversity within colonies or understand the adaptive value of low genetic diversity in large insect societies.     

Musculoskeletal Symptoms in Two Plants in the Electrical Sector

The study consisted of describing, using a questionnaire, the musculoskeletal symptoms in two industries in the electrical sector. The questionnaire was distributed to more than 600 workers in the two industries. The questionnaire described four types of variables: usual population data (age, gender, experience, etc.), certain work variables, the regions of the body affected in the past 12 months and in the past 7 days, and the severity of the symptoms. Ten variables were used to provide a symptom severity index. In the two plants, the women reported more frequent and more serious problems than the men and the least experienced workers were the most affected. In Plant 1, the questionnaire pinpointed two work sectors, whereas in Plant 2, the problems were found not to be concentrated in a few sectors, but distributed among different jobs throughout the entire plant.     

Predictors of conviction and sentencing of DWI offenders in a New Mexico County

OBJECTIVE: To analyze predictors of conviction and dismissal of individuals charged with DWI, and predictors of the sentences of those who are convicted. METHODS: Data come from the Citation Tracking System of the State of New Mexico's Motor Vehicle Division and includes information on all individuals who were arrested for DWI in San Juan County between August 1994 and December 2000. Independent variables were: age, gender, race/ethnicity, waiver of right to an attorney, court of arraignment, year of arrest, BAC, and number of prior DWI arrests. Dependent variables were: (1) conviction or dismissal, (2) jail or no jail, (3) incarceration/treatment or not, (4) fine or no fine, (5) length of jail sentence, (6) waived right of attorney, and (7) magnitude of fine. Multiple linear and logistic regression was used in the analyses. RESULTS: Use of an attorney is associated with reduced likelihood of conviction and, if convicted, in reduced likelihood of jail sentence and reduced jail time, but greater likelihood and magnitude of a fine. Native Americans were more likely than Hispanics and non-Hispanic whites to waive their right to an attorney. Native Americans were most likely to be sentenced to the detention/treatment program. BAC and number of prior arrests were each positively associated with increased likelihood of conviction and more severe sentences. There is also substantial variability in severity of sentencing among courts. CONCLUSION: Likelihood of conviction and severity of sentences are both determined by extra-legal factors, resulting in inconsistent application of the law. This may in turn contribute to a lack of compliance with laws related to DWI.     

Feeding responses to selected alkaloids by gypsy moth larvae, Lymantria dispar (L.)

Deterrent compounds are important in influencing the food selection of many phytophagous insects. Plants containing deterrents, such as alkaloids, are generally unfavored and typically avoided by many polyphagous lepidopteran species, including the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We tested the deterrent effects of eight alkaloids using two-choice feeding bioassays. Each alkaloid was applied at biologically relevant concentrations to glass fiber disks and leaf disks from red oak trees (Quercus rubra) (L.), a plant species highly favored by these larvae. All eight alkaloids tested on glass fiber disks were deterrent to varying degrees. When these alkaloids were applied to leaf disks, only seven were still deterrent. Of these seven, five were less deterrent on leaf disks compared with glass fiber disks, indicating that their potency was dramatically reduced when they were applied to leaf disks. The reduction in deterrency may be attributed to the phagostimulatory effect of red oak leaves in suppressing the negative deterrent effect of these alkaloids, suggesting that individual alkaloids may confer context-dependent deterrent effects in plants in which they occur. This study provides novel insights into the feeding behavioral responses of insect larvae, such as L. dispar, to selected deterrent alkaloids when applied to natural vs artificial substrates and has the potential to suggest deterrent alkaloids as possible candidates for agricultural use.     

Optimization of "Serpa" cheese whey nanofiltration for effluent minimization and by-products recovery

Second cheese whey (SCW) is a by-product of cheese and curd cheese production that is usually not recovered and therefore substantially contributes to the negative environmental impact of the cheese manufacture plants. Membrane technology, namely nanofiltration (NF), is used in this work for the recovery of SCW organic nutrients, resulting from "Serpa" cheese and curd production. The SCW is processed by NF to recover a rich lactose fraction in the concentrate and a process water with a high salt content in the permeate. The permeation experiments were carried out in a plate & frame NF unit, where two NF membranes (NFT50 and HR-95-PP) were characterized and tested. The NF permeation experiments were performed accordingly with two different operation modes: total recirculation and concentration. In order to select the best membrane and operating pressure for the SCW fractionation, total recirculation experiments were carried out. The NF modeling was also performed, in terms of permeate fluxes and rejection coefficients using the resistances-in-series model and the solution-diffusion model, respectively. After the membrane selection, the concentration experiments showed that the selected membrane (NFT50) at 3.0MPa allows a water recovery of approximately 80%, concentrating the SCW nutrients approximately 5 times. Therefore, the NF operation can successfully reduce the wastewater organic load and simultaneously contributes to the valorization of the cheese and curd cheese manufacture by-products.     

Water resources and land use and cover in a humid region: the southeastern United States

It is widely recognized that forest and water resources are intricately linked. Globally, changes in forest cover to accommodate agriculture and urban development introduce additional challenges for water management. The U.S. Southeast typifies this global trend as predictions of land-use change and population growth suggest increased pressure on water resources in coming years. Close attention has long been paid to interactions between people and water in arid regions; however, based on information from regions such as the Southeast, it is evident that much greater focus is required to sustain a high-quality water supply in humid areas as well. To that end, we review hydrological, physicochemical, biological, and human and environmental health responses to conversion of forests to agriculture and urban land uses in the Southeast. Commonly, forest removal leads to increased stream sediment and nutrients, more variable flow, altered habitat and stream and riparian communities, and increased risk of human health effects. Although indicators such as the percentage of impervious cover signify overall watershed alteration, the threshold to disturbance, or the point at which effects can been observed in stream and riparian parameters, can be quite low and often varies with physiographic conditions. In addition to current land use, historical practices can greatly influence current water quality. General inferences of this study may extend to many humid regions concerning climate, environmental thresholds, and the causes and nature of effects.     

Land use effects on macrobenthic communities in southeastern United States tidal creeks

Runoff from impervious land cover has a major impact on headwater tidal creek ecosystems resulting from ever increasing development along the coastline. Tidal creek habitats can serve as "early warning systems" for anthropogenic stressors due to their proximity to the uplands. In this study, the macrobenthic community was sampled along the longitudinal gradient of tidal creeks (i.e., first order, second order, and third order) in North Carolina, South Carolina, and Georgia which varied in their levels of watershed development (salt marsh, forested, suburban, and urban). This study was designed to assess the condition of macrobenthic communities in tidal creek ecosystems under varying levels of anthropogenic stressors and test whether the conclusions of a previous study in South Carolina (Holland et al., J Exp Mar Biol Ecol 298:151-178, 2004) could be generalized to the southeastern USA. Metrics of community-level and species-specific response within tidal creeks draining watersheds of varying degrees of impervious cover suggest the macrobenthic community may be a useful indicator of development in tidal creeks ecosystems. The differences observed when data from all three states were pooled was consistent with previous findings in South Carolina tidal creeks which illustrates that macrobenthic communities in tidal creeks may react to watershed development in similar patterns along the southeastern coast of the USA.