Influence of Insoluble Dietary Cellulose on Digestive Enzyme Activity, Feed Digestibility and Survival in the Red Claw Crayfish, Cherax quadricarinatus (von Martens)

Red claw (Cherax quadricarinatus) is a freshwater crayish species with recognized potential for aquaculture. To better understand the digestive processes and nutritional requirements of red claw, we have examined the effects of dietary cellulose on (1) digestive enzyme activity and diet digestibility and (2) survival rate, feed conversion ratio and growth performance. In the first study, a reference diet (RF) and test diets consisting of 70% RF and 30% a-cellulose or Fuller’s earth were prepared. Analysis of digestive enzyme profiles revealed that amylase and cellulase activities in midgut gland (MG) extracts were highest in the red claw fed on a diet containing 30% Fuller's earth and lowest in those fed on a diet containing 30% a-cellulose. Supplementation of the RF diet with either 30% a-cellulose or Fuller’s earth signi¢cantly reduced apparent dry matter ADMD) and apparent protein digestibilities (APD). In the second study, a feeding trial was conducted using diets supplemented with different levels of a-cellulose. A major finding was that dietary cellulose levels above 12% were correlated with signifcant reductions in survival rate, specific growth rate and feeding efficiency. Based on these findings,we suggest that although cellulase enzymes are present in the red claw digestive system there are no apparent nutritive benefits obtained by including insoluble cellulose in diets for this species

Impact of COVID-19 on Cardiovascular Testing in the United States Versus the Rest of the World

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-U.S. institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection