Spatial and temporal changes in the microbial community in an anaerobic swine waste treatment lagoon

Microorganisms are central to both the beneficial (organic degradation, nutrient removal, biogas production) and detrimental (odor production, pathogen contamination) effects of swine waste storage systems. In this study, both quantitative (real-time polymerase chain reaction) and qualitative (denaturing gradient gel electrophoresis, cloning, sequence analysis) molecular analyses were used to track spatial and temporal changes in the microbial community of swine slurry from a 0.4 ha anaerobic lagoon. The lagoon, located in a region of western Kentucky which has a humid, subtropical environment, was sampled on a monthly basis (n = 10) over a period of one year at four different depths (top, 51 cm from the top, 152 cm from the top, and bottom >198 cm). The concentration and diversity of Bacteroides sp. was seasonal (up to 90% decrease between March and June). Hespellia sp. and other clostridial species, on the other hand, were endemic in the slurry (concentrations up to 1.0 × 10⁷ cells mL^?1 slurry) regardless of time of the year or lagoon depth. Results suggest that there were seasonal effects on the microbial community in the swine lagoon, while the effect of depth was not as pronounced. Seasonal changes in the microbial community in stored wastes may be (directly or indirectly) correlated with changes in malodor emissions from lagoons.     

Molecular phylogeny of the Haplosporidia based on two independent gene sequences

The phylogenetic position of the Haplosporidia has confounded taxonomists for more than a century because of the unique morphology of these parasites. We collected DNA sequence data for small subunit (SSU) ribosomal RNA and actin genes from haplosporidians and other protists for conducting molecular phylogenetic analyses to help elucidate relationships of taxa within the group, as well as placement of this group among Eukaryota. Analyses were conducted using DNA sequence data from more than 100 eukaryotic taxa with various combinations of data sets including nucleotide sequence data for each gene separately and combined, as well as SSU ribosomal DNA data combined with translated actin amino acids. In almost all analyses, the Haplosporidia was sister to the Cercozoa with moderate bootstrap and jackknife support. Analysis with actin amino acid sequences alone grouped haplosporidians with the foraminiferans and cercozoans. The haplosporidians Minchinia and Urosporidium were found to be monophyletic, whereas Haplosporidium was paraphyletic. "Microcell" parasites, Bonamia spp. and Mikrocytos roughleyi, were sister to Minchinia, the most derived genus, with Haplosporidium falling between the "microcells" and the more basal Urosporidium. Two recently discovered parasites, one from abalone in New Zealand and another from spot prawns in British Columbia, fell at the base of the Haplosporidia with very strong support, indicating a taxonomic affinity to this group.     

Neurotransmitter release regulated by a MALS-liprin-alpha presynaptic complex

Synapses are highly specialized intercellular junctions organized by adhesive and scaffolding molecules that align presynaptic vesicular release with postsynaptic neurotransmitter receptors. The MALS/Veli-CASK-Mint-1 complex of PDZ proteins occurs on both sides of the synapse and has the potential to link transsynaptic adhesion molecules to the cytoskeleton. In this study, we purified the MALS protein complex from brain and found liprin-alpha as a major component. Liprin proteins organize the presynaptic active zone and regulate neurotransmitter release. Fittingly, mutant mice lacking all three MALS isoforms died perinatally with difficulty breathing and impaired excitatory synaptic transmission. Excitatory postsynaptic currents were dramatically reduced in autaptic cultures from MALS triple knockout mice due to a presynaptic deficit in vesicle cycling. These findings are consistent with a model whereby the MALS-CASK-liprin-alpha complex recruits components of the synaptic release machinery to adhesive proteins of the active zone.     

Region‐specific effects of oestradiol on adipose‐derived stem cell differentiation in post‐menopausal women

The goal of this study was to determine the effect of acute transdermal 17β‐oestradiol (E₂) on the adipogenic potential of subcutaneous adipose‐derived stem cells (ASC) in post‐menopausal women. Post‐menopausal women (n = 11; mean age 57 ± 4.5 years) were treated for 2 weeks, in a randomized, cross‐over design, with transdermal E₂ (0.15 mg) or placebo patches. Biopsies of abdominal (AB) and femoral (FEM) subcutaneous adipose tissue (SAT) were obtained after each treatment and mature adipocytes were analysed for cell size and ASC for their capacity for proliferation (growth rate), differentiation (triglyceride accumulation) and susceptibility to tumour necrosis factor alpha‐induced apoptosis. Gene expression of oestrogen receptors α and β (ESR1 and ESR2), perilipin 1 and hormone‐sensitive lipase (HSL), was also assessed. In FEM SAT, but not AB SAT, 2 weeks of E₂ significantly (P = 0.03) increased ASC differentiation and whole SAT HSL mRNA expression (P = 0.03) compared to placebo. These changes were not associated with mRNA expression of oestrogen receptors α and β, but HSL expression was significantly increased in FEM SAT with transdermal E₂ treatment. Adipose‐derived stem cells proliferation and apoptosis did not change in either SAT depot after E₂ compared with placebo. Short‐term E₂ appeared to increase the adipogenic potential of FEM, but not AB, SAT in post‐menopausal women with possible implications for metabolic disease. Future studies are needed to determine longer term impact of E₂ on regional SAT accumulation in the context of positive energy imbalance.     

Hyperspectral Remote Sensing of Canopy Biodiversity in Hawaiian Lowland Rainforests

Mapping biological diversity is a high priority for conservation research, management and policy development, but few studies have provided diversity data at high spatial resolution from remote sensing. We used airborne imaging spectroscopy to map woody vascular plant species richness in lowland tropical forest ecosystems in Hawai’i. Hyperspectral signatures spanning the 400–2,500 nm wavelength range acquired by the NASA Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) were analyzed at 17 forest sites with species richness values ranging from 1 to 17 species per 0.1–0.3 ha. Spatial variation (range) in the shape of the AVIRIS spectra (derivative reflectance) in wavelength regions associated with upper-canopy pigments, water, and nitrogen content were well correlated with species richness across field sites. An analysis of leaf chlorophyll, water, and nitrogen content within and across species suggested that increasing spectral diversity was linked to increasing species richness by way of increasing biochemical diversity. A linear regression analysis showed that species richness was predicted by a combination of four biochemically-distinct wavelength observations centered at 530, 720, 1,201, and 1,523 nm (r ² = 0.85, p < 0.01). This relationship was used to map species richness at approximately 0.1 ha resolution in lowland forest reserves throughout the study region. Future remote sensing studies of biodiversity will benefit from explicitly connecting chemical and physical properties of the organisms to remotely sensed data.     

Interaction between RAX and PKR modulates the effect of ethanol on protein synthesis and survival of neurons

Ethanol exposure inhibits protein synthesis and causes cell death in the developing central nervous system. The double-stranded RNA (dsRNA)-activated protein kinase (PKR), a serine/threonine protein kinase, plays an important role in translational regulation and cell survival. PKR has been well known for its anti-viral response. Upon activation by viral infection or dsRNA, PKR phosphorylates its substrate, the alpha-subunit of eukaryotic translation initiation factor-2 (eIF2alpha) leading to inhibition of translation initiation. It has recently been shown that, in the absence of a virus or dsRNA, PKR can be activated by direct interactions with its protein activators, PACT, or its mouse homologue, RAX. We have demonstrated that exposure to ethanol increased the phosphorylation of PKR and eIF2alpha in the developing cerebellum. The effect of ethanol on PKR/eIF2alpha phosphorylation positively correlated to the expression of PACT/RAX in cultured neuronal cells. Using PKR inhibitors and PKR null mouse fibroblasts, we verified that ethanol-induced eIF2alpha phosphorylation was mediated by PKR. Overexpression of a wild-type RAX dramatically enhanced sensitivity to ethanol-induced PKR/eIF2alpha phosphorylation, as well as translational inhibition and cell death. In contrast, overexpression of a mutant (S18A) RAX inhibited ethanol-mediated PKR/eIF2alpha activation. Ethanol promoted PKR and RAX association in cells expressing wild-type RAX but not in cells expressing S18A RAX. S18A RAX functioned as a dominant negative protein and blocked ethanol-induced inhibition of protein synthesis and cell death. Our results suggest that the interactions between PKR and PACT/RAX modulate the effect of ethanol on protein synthesis and cell survival in the central nervous system.     

Testosterone and its effects on courtship in golden-collared manakins (Manacus vitellinus): seasonal, sex, and age differences

Male golden-collared manakins gather on leks and perform an acrobatic display to attract females. In temperate breeding species, testosterone (T) activation of courtship displays has been well studied. Few studies have examined T activation of displays in tropical species; even fewer have explored the activational role of T in elaborate courtship displays such as in the manakin. In some tropical species, including manakins, territorial aggression or song behavior are uncoupled from T. We have previously shown that T activates display behavior in manakin males when endogenous T levels are low in the non-courtship season. To understand how T functions in breeding birds, we examined T levels in a large group of manakins sampled during the courtship and non-courtship season. In addition, during the courtship season, we gave T implants to adult males, juvenile males, and females. We found that T levels were low during the non-courtship season and comparatively higher on average during the courtship season. However, T levels were low in many adult males during the courtship season, especially when compared to temperate breeding species. Regardless of initial endogenous T levels during the courtship season, T implants did not increase the display frequency of adult males. T-treated females and juvenile males did display under similar conditions. Our data suggest that the effects of T on manakin display vary with season, sex, and age and that high T is not necessary for display.     

Retained in HIV Care But Not on Antiretroviral Treatment: A Qualitative Patient-Provider Dyadic Study

Background

Patients retained in HIV care but not on antiretroviral therapy (ART) represent an important part of the HIV care cascade in the United States. Even in an era of more tolerable and efficacious ART, decision making in regards to ART offer and uptake remains complex and calls for exploration of both patient and provider perspectives. We sought to understand reasons for lack of ART usage in patients meeting the Health Resources Services Administration definition of retention as well as what motivated HIV primary care appointment attendance in the absence of ART.

Methods and Findings

We conducted a qualitative study consisting of 70 in-depth interviews with ART-naïve and ART-experienced patients off ART and their primary care providers in two urban safety-net HIV clinics in San Francisco and New York. Twenty patients and their providers were interviewed separately at baseline, and 15 dyads were interviewed again after at least 3 mo and another clinic visit in order to understand any ART use in the interim. We applied dyadic analysis to our data. Nearly all patients were willing to consider ART, and 40% of the sample went on ART, citing education on newer antiretroviral drugs, acceptance of HIV diagnosis, social support, and increased confidence in their ability to adhere as facilitators. However, the strength of the provider recommendation of ART played an important role. Many patients had internalized messages from providers that their health was too good to warrant ART. In addition, providers, while demonstrating patient-centered care through sensitivity to patients experiencing psychosocial instability, frequently muted the offer of ART, at times unintentionally. In the absence of ART, lab monitoring, provider relationships, access to social services, opiate pain medications, and acute symptoms motivated care. The main limitations of this study were that treatment as prevention was not explored in depth and that participants were recruited from academic HIV clinics in the US, making the findings most generalizable to this setting.

Conclusions

Provider communication with regard to ART is a key focus for further exploration and intervention in order to increase ART uptake for those retained in HIV care.