A Tale of Two Sylamores: Understanding Relationships Among Land Use, Nutrients, and Aquatic Communities Across a Subsidy-Stress Gradient

Agricultural land use is known to degrade aquatic systems with high inputs of nutrients, sediments, and pesticides. Increased nutrients can lead to increased algal growth and thus possible hypoxic conditions in slow moving water, while increased sediment loads have been shown to obstruct light and reduce substrate stability. These conditions negatively impact primary producers, macroinvertebrates, and fish. However, small-scale changes in land use can subsidize an aquatic ecosystem instead, where an increase in nutrients allows nutrient-limited biota to flourish, and minor increases in sedimentation may help support populations of collector-filterers. The stimulation in performance caused by small disturbances is part of the subsidy-stress gradient, where increasing perturbation subsidizes an ecosystem until a certain threshold is reached, at which a decline in performance and increased variability starts to occur. The North and South Sylamore watersheds in north Arkansas provide a useful template to investigate the subsidy-stress gradient in relation to land use. North Sylamore flows through the Ozark National Forest and has a heavily forested catchment, while South Sylamore flows through mostly private land, some of which is pasture (23%). Physicochemical, macroinvertebrate, and fish data were collected from multiple sites within each watershed to determine if South Sylamore is exhibiting a response to pasture/agriculture characteristic of a subsidy-stress gradient. Sites within South Sylamore had significantly higher nitrate levels, larger macroinvertebrate populations dominated by collector-filterers, and greater abundance of algivorous fish, suggesting South Sylamore may be subsidized by the surrounding pastoral lands. However, South Sylamore also had a significantly lower proportional abundance of sensitive macroinvertebrate taxa and more unique tolerant fish taxa, suggesting South Sylamore is experiencing stress as well. Habitat quality of South Sylamore could be improved by restoration of trees within the riparian zone. Monitoring aquatic systems for subsidy-stress responses can inform restoration/management decisions and guide intervention prior to watersheds and aquatic communities becoming overly stressed

Rediscovery of the Pallid Shiner, \u3ci\u3eHybopsis amnis\u3c/i\u3e, in the Black River System of Arkansas and Missouri Including Notes on Ecology and Life History

The Pallid Shiner, Hybopsis amnis, is a rare and understudied minnow with little information about its ecology. This species is listed as a Species of Greatest Conservation Need (SGCN) throughout much of its range and is generally considered to be declining. It had not been detected in the Black River system of Missouri and Arkansas in over 75 years, or the state of Missouri in over 60 years. We sampled over 100 sites in the Black River system between 2017 and 2020 to assess temporal trends in fish assemblage structure and to update the status of SGCN species in this drainage. We collected 226 H. amnis at seven different sites in the Black River system. We measured total lengths to estimate age classes and year of spawning. Corresponding habitat and year class data indicate this species may spawn in late winter to early spring and rely on floodplain habitat for spawning and recruitment. The apparent decline of H. amnis in other systems may be a result of reduced floodplain connectivity

Guest Recital: Smokey Mountain Chamber Players

Kemp Recital Hall Tuesday Evening January 23, 1996 8:00p.m

Improving Community Advisory Board Engagement In Precision Medicine Research To Reduce Health Disparities

Community Advisory Boards (CABs) are used in efforts to reduce health disparities; however, there is little documentation in the literature regarding their use in precision medicine research. In this case study, an academic-CAB partnership developed a questionnaire and patient educational materials for two precision smoking cessation interventions that involved use of genetic information. The community-engaged research (CEnR) literature provided a framework for enhancing benefits to CAB members involved in developing research documents for use with a low-income, ethnically diverse population of smokers. The academic partners integrated three CEnR strategies: 1) in-meeting statements acknowledging their desire to learn from community partners, 2) in-meeting written feedback to and from community partners, and 3) a survey to obtain CAB member feedback post-meetings. Strategies 1 and 2 yielded modifications to pertinent study materials, as well as suggestions for improving meeting operations that were then adopted, as appropriate, by the academic partners. The survey indicated that CAB members valued the meeting procedure changes which appeared to have contributed to improvements in attendance and satisfaction with the meetings. Further operationalization of relevant partnership constructs and development of tools for measuring these aspects of community-academic partnerships is warranted to support community engagement in precision medicine research studies

Two novel human NUMB isoforms provide a potential link between development and cancer

We previously identified four functionally distinct human NUMB isoforms. Here, we report the identification of two additional isoforms and propose a link between the expression of these isoforms and cancer. These novel isoforms, NUMB5 and NUMB6, lack exon 10 and are expressed in cells known for polarity and migratory behavior, such as human amniotic fluid cells, glioblastoma and metastatic tumor cells. RT-PCR and luciferase assays demonstrate that NUMB5 and NUMB6 are less antagonistic to NOTCH signaling than other NUMB isoforms. Immunocytochemistry analyses show that NUMB5 and NUMB6 interact and complex with CDC42, vimentin and the CDC42 regulator IQGAP1 (IQ (motif) GTPase activating protein 1). Furthermore, the ectopic expression of NUMB5 and NUMB6 induces the formation of lamellipodia (NUMB5) and filopodia (NUMB6) in a CDC42- and RAC1-dependent manner. These results are complemented by in vitro and in vivo studies, demonstrating that NUMB5 and NUMB6 alter the migratory behavior of cells. Together, these novel isoforms may play a role in further understanding the NUMB function in development and cancer

Insulin resistance in lean and overweight non-diabetic Caucasian adults: Study of its relationship with liver triglyceride content, waist circumference and BMI

Insulin resistance is the pathophysiological precursor of type 2 diabetes mellitus (DM-2), and its relationship with non-alcoholic fatty liver disease (NAFLD) has been widely studied in patients with obesity or metabolic syndrome using not only ultrasound but also liver biopsies or proton magnetic resonance spectroscopy (H1-MRS) to assess liver fat content. In contrast, there are no studies on insulin resistance and NAFLD in lean or overweight Caucasian individuals using H1-MRS or liver biopsies for the quantification of hepatic triglyceride content. Our objectives were to study the presence of insulin resistance in lean and overweight Caucasian adults and investigate its possible relationship with liver triglyceride content, waist circumference (as proxy of visceral adiposity), BMI, and cardiometabolic risk factors.A cross-sectional study was conducted in 113 non-obese, non-diabetic individuals classified as overweight (BMI 25–29.9 kg/m2) or lean (BMI 19.5–24.9 kg/m2). Hepatic triglyceride content was quantified by 3T H1-MRS. NAFLD was defined as hepatic triglyceride content >5.56%. Insulin resistance (HOMA-IR), serum adiponectin, and tumor necrosis factor (TNF) were determined.HOMA-IR was significantly correlated with hepatic triglyceride content (r:0.76; p<0.0001). The lean-with-NAFLD group had significantly higher HOMA-IR (p<0.001) and lower serum adiponectin (p<0.05) than the overweight-without-NAFLD group. Insulin resistance was independently associated with NAFLD but not with waist circumference or BMI. Regression analysis showed hepatic triglyceride content to be the most important determinant of insulin resistance (p<0.01).Our findings suggest that NAFLD, once established, seems to be involved in insulin resistance and cardio-metabolic risk factors above and beyond waist circumference and BMI in non-obese, non-diabetic Caucasian individuals

Cleavage of intron from the standard or non-standard position of the precursor tRNA by the splicing endonuclease of Aeropyrum pernix, a hyper-thermophilic Crenarchaeon, involves a novel RNA recognition site in the Crenarchaea specific loop

In Crenarchaea, several tRNA genes are predicted to express precursor-tRNAs (pre-tRNAs) with canonical or non-canonical introns at various positions. We initially focused on the tRNAThr species of hyperthermophilic crenarchaeon, Aeropyrum pernix (APE) and found that in the living APE cells three tRNAThr species were transcribed and subsequently matured to functional tRNAs. During maturation, introns in two of them were cleaved from standard and non-standard positions. Biochemical studies revealed that the APE splicing endonuclease (APE-EndA) removed both types of introns, including the non-canonical introns, without any nucleotide modification. To clarify the underlying reasons for broad substrate specificity of APE-EndA, we determined the crystal structure of wild-type APE-EndA and subsequently compared its structure with that of Archaeaoglobus fulgidus (AFU)-EndA, which has narrow substrate specificity. Remarkably, structural comparison revealed that APE-EndA possesses a Crenarchaea specific loop (CSL). Introduction of CSL into AFU-EndA enhanced its intron-cleaving activity irrespective of the position or motif of the intron. Thus, our biochemical and crystallographic analyses of the chimera-EndA demonstrated that the CSL is responsible for the broad substrate specificity of APE-EndA. Furthermore, mutagenesis studies revealed that Lys44 in CSL functions as the RNA recognition site