High-efficiency chrome tanning using pre-treatments

Content: Pre-treatments are widely used during tanning processes as to improve the performance of the main tannage. Synchrotron small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to study four common types of pre-treatments, viz. monodentate complexing agent (sodium formate, SF), chelating agent (disodium phthalate, DSP), covalent cross-linker (glutaraldehyde, GA) and nanoclay (sodium montmorillonite, MMT) about their effects on chromium-collagen cross-linking reaction during tanning. Based on the results, the performance of chromium-collagen cross-linking with and without pre-treatments was presented considering five aspects: cross-linking, the level of hydration, hydrothermal stability, uniformity through leather cross-section and the uptake of chrome. Comparing to the original ThruBlu chrome tanning, at the same chrome offers, leather pre-treated using SF, DSP and MMT showed improved hydrothermal stability, uniformity and the level of hydration, while GA showed decreased hydration. All of the pre-treatments reduce surface fixation by decreasing the reactivity of chromium with collagen. Changes in the reaction performance can influence the properties of the leather products as well as the efficiency of the leather manufacturing processes. Insights into the structural changes of collagen during tanning with varied reaction conditions can guide the design of novel, benign tanning processes to reduce environmental impact. Take-Away: 1. Uniformity of the hydrothermal stability through leather cross-section were improved by all of the studied pre-treatments. 2. Reactivity of chromium to cross-link with collagen was reduced as a result of the complexing, covalent cross-linking, or preferential adsorption. 3. Complexing agents and nanoclay pre-treatments tend to retain collagen bound water, while covalent cross-linker causing decrease in the level of hydration of collagen

Towards a molecular level understanding of chrome tanning: Interplay between collagen structure and reactivity

Content: Synchrotron small-angle X-ray scattering (SAXS) technique was applied to leather research to understand the changes in molecular-level collagen structure during tanning and denaturation (shrinkage), which can help reduce the environmental impact from the extensive chrome usage. Based on SAXS results from realtime denaturation experiments on leather samples, we established a mechanistic model of chrome tanning indicated by the structural changes of collagen. It suggests that only a low level of chromium species is effectively involved in the cross-linking with collagen, which highlights the overuse of chrome during conventional tanning processes. Any extra amount of chrome added, however, can support the stabilisation of collagen possibly via a non-covalent mechanism. Such mechanism points towards a more environment-friendly tanning method by using suitable supplementary reagents to benefit tanning effect non-covalently instead of chrome. By pre-treating with complexing agents such as sodium formate and disodium phthalate, as well as nanoclay (sodium montmorillonite), the uniformity through bovine hide collagen matrix were improved significantly. These pre-treatments effectively reduce the reactivity of chromium during its cross-linking reaction with collagen while retaining its bound water. However, collagen pre-treated with a covalent cross-linker (glutaraldehyde) results in a decrease in both chromium-collagen cross-linking and bound water while improving uniformity. These molecular-level insights can be developed into metrics to guide us towards a more sustainable future for the leather industry. The coating on collagen fibrils can provide a pseudo-stabilisation effect of increasing the heat resistance of collagen. A group of tanning experiments were also conducted in situ on the SAXS beamline to observe the different mechanisms of free-of-chrome alternative tannages as potential replacements. Overall, synchrotron SAXS provides valuable information about collagen structure changes that could lead to more efficient use of chrome (or other tanning agents) in the global leather tanning industry. Take-Away: 1. Kinetics of hydrothermal denaturation and collagen crosslinking mechanism proceed through different pathways 2. Alternative chemistries to enhance chrome uptake at low offers. 3. The role of collagen structure studies in understanding tanning mechanim

An Experimental Comparison of the Effect of Teacher Versus Self‑Evaluation/Self‑Reflection Feedback on College Students’ Behavioral Observation Skills

An experimental investigation of the effectiveness of two types of feedback on college students’ acquisition of behavioral observation skills was conducted. Special education and psychology students completed two training assignments involving behavioral observations of students engaging in problem behavior. Depending on the condition to which they were randomly assigned, participants experienced either teacher or self-evaluation/self-reflection feedback immediately after each assignment was completed. Participants in the teacher feedback condition scored higher on the post-training assignments and viewed it more positively than those in the self- evaluation/self-reflection condition. Additional research is needed to identify the relevant variables contributing to effective teacher feedback since it is a frequent component of instructional situations

Bringing gender into research with international students

This chapter considers the role of gender identity and gendered experiences in research with international students. Although gender is an area of growing research interest in this subfield, there are a number of considerations that we raise for further contemplation. The first is the need to consider cultural variations in conceptualisations of gender and gendered norms, which may lead international students to (re)negotiating normative expectations of what it means to ‘do’ and express gender. The second is the tendency for research to frame women in particular as vulnerable research subjects while ignoring their agency. The third is the tendency for research about the intersection of gender and international student status to focus on women’s experiences, with limited research about men international students or those who identify as transgender, non-binary, or third gender. Finally, we consider the ways research processes may be gendered, regardless of whether the subject is ‘about gender’. Altogether, we offer suggestions for areas with significant research gaps and considerations for gendering research with international students

Imagine Community, Imagine Home (Chicopee, MA)

The goal of the Master of Regional Planning Studio is to develop a student’s techniques for collecting, analyzing, and synthesizing spatial and non-spatial data and then presenting that collective data in a manner (i.e., report, video, presentation, and charettes) that is understandable to academics, professionals, and the public. Planning Studio allows students to integrate knowledge from coursework and research, and apply such knowledge to resolving representative planning problems. At UMASS Amherst, these problems are found in neighborhood, rural, urban, and/or regional settings. For the fall 2018 Planning Studio, Chicopee tasked the Masters of Regional Planning Studio to prepare a Housing Plan that details a comprehensive approach for housing development within the West End neighborhood over the next fifteen (15) years. The housing plan will include the following components: Analysis of historic housing development patterns; Analysis of currently proposed/advancing housing projects in the neighborhood; Analysis of future housing needs/demands; Review of market conditions in support of market rate, workforce, and low-income housing projects; Analysis of funding mechanisms for housing projects; Development of neighborhood and site specific recommendations to support desired housing projects including suggestions to improve zoning ordinances, density parameters, urban improvements needed to support such housing development, opportunities for mixed-use projects, and site specific development pro-forma

Group A Streptococcal S Protein Utilizes Red Blood Cells as Immune Camouflage and Is a Critical Determinant for Immune Evasion.

Group A Streptococcus (GAS) is a human-specific pathogen that evades the host immune response through the elaboration of multiple virulence factors. Although many of these factors have been studied, numerous proteins encoded by the GAS genome are of unknown function. Herein, we characterize a biomimetic red blood cell (RBC)-captured protein of unknown function-annotated subsequently as S protein-in GAS pathophysiology. S protein maintains the hydrophobic properties of GAS, and its absence reduces survival in human blood. S protein facilitates GAS coating with lysed RBCs to promote molecular mimicry, which increases virulence in vitro and in vivo. Proteomic profiling reveals that the removal of S protein from GAS alters cellular and extracellular protein landscapes and is accompanied by a decrease in the abundance of several key GAS virulence determinants. In vivo, the absence of S protein results in a striking attenuation of virulence and promotes a robust immune response and immunological memory

Exploratory application of a cannulation model in recently weaned pigs to monitor longitudinal changes in the enteric microbiome across varied porcine reproductive and respiratory syndrome virus (PRRSV) infection status

The enteric microbiome and its possible modulation to improve feed conversion or vaccine efficacy is gaining more attention in pigs. Weaning pigs from their dam on top of many routine procedures is stressful. A better understanding of the impact of this process on the microbiome may be important to improve pig production. The objective of this study was to develop a weaner pig cannulation model allowing ileum content collection from the same pig over time for 16S rRNA sequencing under different porcine reproductive and respiratory syndrome virus (PRRSV) infection status. Methods: Fifteen 3-week-old pigs underwent abdominal surgery and were fitted with an ileum cannula and ileum contents were collected over time. In this pilot study, treatment groups included a NEG-CONTROL group (no vaccination, no PRRSV challenge), a POS-CONTROL group (no vaccination, PRRSV challenge), a VAC-PRRSV group (vaccinated, PRRSV challenged), a VAC-PRO-PRRSV group (supplemented with probiotics, vaccinated, challenged with PRRSV) and a VAC-ANTI-PRRSV group (antibiotic administration, vaccinated, PRRSV challenged). We assessed the microbiome over time, measured anti-PRRSV serum antibodies, PRRSV load in serum and nasal samples, and severity of lung lesions. Results: Vaccination was protective against PRRSV challenge, irrespective of other treatments. All vaccinated pigs mounted an immune response to PRRSV within 1 week after vaccination. A discernible impact of treatment on the diversity, structure, and taxonomic abundance of enteric microbiome among the groups was not observed. Instead, significant influences on ileum microbiome were observed in relation to time and treatment. Discussion: The cannulation model described in this pilot study has the potential to be useful to study the impact of weaning, vaccination, disease challenge, and antimicrobial administration on the enteric microbiome and its impact on pig health and production. Remarkably, despite the cannulation procedures, all vaccinated pigs exhibited robust immune responses and remained protected against PRRSV challenge, as evidenced by development of anti-PRRSV serum antibodies and viral shedding data

Death effector domain-containing protein induces vulnerability to cell cycle inhibition in triple-negative breast cancer

Lacking targetable molecular drivers, triple-negative breast cancer (TNBC) is the most clinically challenging subtype of breast cancer. In this study, we reveal that Death Effector Domain-containing DNA-binding protein (DEDD), which is overexpressed in > 60% of TNBCs, drives a mitogen-independent G1/S cell cycle transition through cytoplasm localization. The gain of cytosolic DEDD enhances cyclin D1 expression by interacting with heat shock 71 kDa protein 8 (HSC70). Concurrently, DEDD interacts with Rb family proteins and promotes their proteasome-mediated degradation. DEDD overexpression renders TNBCs vulnerable to cell cycle inhibition. Patients with TNBC have been excluded from CDK 4/6 inhibitor clinical trials due to the perceived high frequency of Rb-loss in TNBCs. Interestingly, our study demonstrated that, irrespective of Rb status, TNBCs with DEDD overexpression exhibit a DEDD-dependent vulnerability to combinatorial treatment with CDK4/6 inhibitor and EGFR inhibitor in vitro and in vivo. Thus, our study provided a rationale for the clinical application of CDK4/6 inhibitor combinatorial regimens for patients with TNBC

Treatment patterns and outcomes following disease progression on anti-PD-1 therapies for advanced melanoma

Background: Anti-PD-1-based therapies prolong survival in advanced melanoma, but disease progression is common. This study evaluated treatment patterns and overall survival (OS) after anti-PD-1 progression. Methods: Retrospective data from patients with advanced melanoma and progression on anti-PD-1 treatment between 2014 and 2019 were taken from Flatiron Health, which reflects largely community practice. Treatment patterns and OS were analyzed for BRAF mutant (mt) and wild-type (wt) subgroups; OS was also examined across all patients. Results: Progression following anti-PD-1 was recorded for 679 patients. Median OS ranged from 5.0 to 11.3 months. Of 275 BRAFmt and 374 BRAFwt patients, 113 (41.1%) and 228 (61.0%) received no subsequent therapy, respectively. However, 48.4% of BRAFmt and 57.8% of BRAFwt patients continued anti-PD-1 treatment beyond progression. Conclusion: This real-world study underscores the need for effective treatments for advanced melanoma post-progression on anti-PD-1 therapy

The evolutionary emergence of stochastic phenotype switching in bacteria

Stochastic phenotype switching – or bet hedging – is a pervasive feature of living systems and common in bacteria that experience fluctuating (unpredictable) environmental conditions. Under such conditions, the capacity to generate variable offspring spreads the risk of being maladapted in the present environment, against offspring likely to have some chance of survival in the future. While a rich subject for theoretical studies, little is known about the selective causes responsible for the evolutionary emergence of stochastic phenotype switching. Here we review recent work – both theoretical and experimental – that sheds light on ecological factors that favour switching types over non-switching types. Of particular relevance is an experiment that provided evidence for an adaptive origin of stochastic phenotype switching by subjecting bacterial populations to a selective regime that mimicked essential features of the host immune response. Central to the emergence of switching types was frequent imposition of ‘exclusion rules’ and ‘population bottlenecks’ – two complementary faces of frequency dependent selection. While features of the immune response, exclusion rules and bottlenecks are likely to operate in many natural environments. Together these factors define a set of selective conditions relevant to the evolution of stochastic switching, including antigenic variation and bacterial persistence