Boost in Visitor Numbers Post COVID-19 Shutdown: Consequences for an Alpine National Park

The coronavirus disease 2019 (COVID-19) pandemic changed recreation patterns worldwide. Increases in protected areas' visitor numbers were reported along with associated challenges. Changes in visitor numbers, composition, and motivation remain mostly unrecorded due to a lack of baseline records for comparison. We aimed to fill this gap with a study in the Swiss National Park (SNP), an International Union for Conservation of Nature (IUCN) strict nature reserve in the European Alps, where visitor numbers strongly increased in 2020 and 2021 compared to previous years. In summer 2020, we repeated a visitor survey previously conducted in 2006 and 2012, complemented by assessments of COVID-19-related motivations. To deepen our understanding of the COVID-19 context, we conducted semistructured interviews with SNP visitors. In general, COVID-19-related factors were a strong driver of increased visitor numbers. A fifth of survey respondents indicated that they would not have visited the SNP but for the pandemic, with most of them being first-time or infrequent visitors. Furthermore, our data showed that more young, domestic, and less experienced visitors came to the park. We discuss impacts and implications for practitioners and researchers (ie the need to better sensitize newcomers to environmental issues) and argue that our study holds insights for park managers worldwide

Alterations in Postprandial Hepatic Glycogen Metabolism in Type 2 Diabetes

Decreased skeletal muscle glucose disposal and increased endogenous glucose production (EGP) contribute to postprandial hyperglycemia in type 2 diabetes, but the contribution of hepatic glycogen metabolism remains uncertain. Hepatic glycogen metabolism and EGP were monitored in type 2 diabetic patients and nondiabetic volunteer control subjects (CON) after mixed meal ingestion and during hyperglycemic-hyperinsulinemic-somatostatin clamps applying 13C nuclear magnetic resonance spectroscopy (NMRS) and variable infusion dual-tracer technique. Hepatocellular lipid (HCL) content was quantified by 1H NMRS. Before dinner, hepatic glycogen was lower in type 2 diabetic patients (227 ± 6 vs. CON: 275 ± 10 mmol/l liver, P < 0.001). After meal ingestion, net synthetic rates were 0.76 ± 0.16 (type 2 diabetic patients) and 1.36 ± 0.15 mg · kg−1 · min−1 (CON, P < 0.02), resulting in peak concentrations of 283 ± 15 and 360 ± 11 mmol/l liver. Postprandial rates of EGP were ∼0.3 mg · kg−1 · min−1 (30–170 min; P < 0.05 vs. CON) higher in type 2 diabetic patients. Under clamp conditions, type 2 diabetic patients featured ∼54% lower (P < 0.03) net hepatic glycogen synthesis and ∼0.5 mg · kg−1 · min−1 higher (P < 0.02) EGP. Hepatic glucose storage negatively correlated with HCL content (R = −0.602, P < 0.05). Type 2 diabetic patients exhibit 1) reduction of postprandial hepatic glycogen synthesis, 2) temporarily impaired suppression of EGP, and 3) no normalization of these defects by controlled hyperglycemic hyperinsulinemia. Thus, impaired insulin sensitivity and/or chronic glucolipotoxicity in addition to the effects of an altered insulin-to-glucagon ratio or increased free fatty acids accounts for defective hepatic glycogen metabolism in type 2 diabetic patients

Plastic adaptations of foraging strategies to variation in forage quality in Alpine chamois

Foraging efficiency strongly affects individual fitness and is influenced by diverse factors such as the food quality and quantity, as well as intra- and interspecific interactions. We investigated whether Alpine chamois (Rupicapra rupicapra L., 1758) in a protected area in the Swiss Alps adapted their foraging behaviour to forage availability and quality by modeling the bite and step rates of individuals on vegetation nitrogen content, relative plant cover, sex, daytime, air temperature and slope. Vegetation characteristics were derived using remote sensing data from airborne imaging spectroscopy datasets and feeding locations determined using a theodolite. Chamois increased their bite rates with decreasing forage nitrogen content, decreasing slope and increasing temperature. Step rates were higher at high temperatures and decreased with increasing relative plant cover. Males showed higher bite rates and lower step rates than females. Daytime had no influence on either bite or step rates. An increase in bite rate may represent a plastic adaptation of foraging behaviour to compensate for lower nutritional quality of the available vegetation. Our results show variability in foraging behaviour according to both vegetation characteristics and the physical environment and emphasize the use of remote sensing data to investigate relationships between habitat and subtle behavioural adaptations in ungulates

Impact of family history on relations between insulin resistance, LDL cholesterol and carotid IMT in healthy adults

Background Insulin resistance (IR) is implicated as an independent risk factor for vascular disease. The aim of this study was to assess the impact of family history (FH) of type 2 diabetes (T2DM) and/or cardiovascular disease (CVD) on the associations between IR, low-density-lipoprotein cholesterol (LDL-C) and subclinical atherosclerosis (common and internal carotid artery intima media thickness (IMT)) in healthy European adults. Methods Participants (n=1048) in the Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) study were grouped according to family history of: (i) type 2 diabetes (FH-T2DM); (ii) cardiovascular disease (FH-CVD); (iii) both (FH-BOTH); or (iv) neither (CON). Insulin resistance (M-value, hyperinsulinaemic euglycaemic clamp), LDL-C and IMT were examined in relation to FH in all available participants, and then within subcohorts (highest quintiles) with higher LDL-C (>3.5 mmol/l (>135 mg/dl), n=252) or greater IR (M-value<5 mg/min/kg, n=299). \ud Results Carotid IMTs were comparable across the four FH groups, but insulin sensitivity (M-value) was lower (p<0.01) in FH-T2DM (6.1 +/- 2.6 mg/min/kg than in either CON (6.9 +/- 2.9 mg/min/kg) or FH-CVD (7.1 +/- 2.7 mg/min/kg). Within the highest LDL-C quintile, those with FH-CVD (or FH-BOTH) had higher common and internal carotid IMT (6-12%, p<0.05 vs CON). In contrast, within the most IR quintile, FH-CVD was not associated with IMT. Conclusion In this cross-sectional analysis, family history of T2DM (but not of CVD) was associated with IR. In the presence of elevated LDL-C, FH-CVD (but not FH-T2DM) was associated with increased carotid IMT

Adequately adapted insulin secretion and decreased hepatic insulin extraction cause elevated insulin concentrations in insulin resistant non-diabetic adrenal incidentaloma patients.

BACKGROUND:Insulin-resistance is commonly found in adrenal incidentaloma (AI) patients. However, little is known about beta-cell secretion in AI, because comparisons are difficult, since beta-cell-function varies with altered insulin-sensitivity. OBJECTIVES:To retrospectively analyze beta-cell function in non-diabetic AI, compared to healthy controls (CON). METHODS:AI (n=217, 34%males, 57 ± 1 years, body-mass-index:27.7 ± 0.3 kg/m(2)) and CON [n = 25, 32%males, 56 ± 1 years, 26.7 ± 0.8 kg/m(2)] with comparable anthropometry (p ≥ 0.31) underwent oral-glucose-tolerance-tests (OGTTs) with glucose, insulin, and C-peptide measurements. 1mg-dexamethasone-suppression-tests were performed in AI. AI were divided according to post-dexamethasone-suppression-test cortisol-thresholds of 1.8 and 5 µg/dL into 3 subgroups: pDexa<1.8 µg/dL, pDexa1.8-5 µg/dL and pDexa>5 µg/dL. Using mathematical modeling, whole-body insulin-sensitivity [Clamp-like-Index (CLIX)], insulinogenic Index, Disposition Index, Adaptation Index, and hepatic insulin extraction were calculated. RESULTS:CLIX was lower in AI combined (4.9 ± 0.2 mg · kg(-1) · min(-1)), pDexa<1.8 µg/dL (4.9 ± 0.3) and pDexa1.8-5 µg/dL (4.7 ± 0.3, p<0.04 vs.CON:6.7 ± 0.4). Insulinogenic and Disposition Indexes were 35%-97% higher in AI and each subgroup (p<0.008 vs.CON), whereas C-peptide-derived Adaptation Index, compensating for insulin-resistance, was comparable between AI, subgroups, and CON. Mathematical estimation of insulin-derived (insulinogenic and Disposition) Indexes from associations to insulin-sensitivity in CON revealed that AI-subgroups had ~19%-32% higher insulin-secretion than expectable. These insulin-secretion-index differences negatively (r=-0.45, p<0.001) correlated with hepatic insulin extraction, which was 13-16% lower in AI and subgroups (p<0.003 vs.CON). CONCLUSIONS:AI-patients show insulin-resistance, but adequately adapted insulin secretion with higher insulin concentrations during an OGTT, because of decreased hepatic insulin extraction; this finding affects all AI-patients, regardless of dexamethasone-suppression-test outcome