Adjunct Instructors’ Opportunities for Learning Through Engagement with a Research-Based Mathematics Curriculum

There is a growing need to retain students in STEM fields and majors in the U.S. Improving students’ experience in early mathematics courses like Precalculus can influence students’ decisions to remain in STEM fields. Teachers can play an important role in providing effective learning experiences to the students. Supporting teachers and providing professional development can help the teachers in facilitating student learning. When it comes to implementing research-based mathematics curricula, teachers are key players in making the curriculum come alive inside their classrooms. The challenges that teachers face when implementing a research-based mathematics curriculum can provide opportunities for their own learning. As they engage with the curricular resources, the new curriculum challenges the teachers’ current knowledge and teaching practice. In this dissertation I have explored three adjunct instructors’ engagement with a research-based mathematics curriculum over the course of two semesters. Engagement with the curricular resources provided opportunities for their learning, as the instructors planned and enacted the curriculum, discussed it while collaborating with colleagues or reflecting. Some of these opportunities were availed and some were left unexplored. Findings of this study have implications for developing effective professional development programs for adjunct instructors

Ecosystem Services in the Changing Climate: Calling Attention for the Conservation of Tropical and Subtropical Forests

Tropical and subtropical forests have diverse ecological functions but are most disturbed due to climatic changes. Peer-reviewed articles, books and reports were searched and downloaded to analyze the effect of climatic changes on tropical and subtropical forests and highlight the need for conservation efforts to ensure sustainable supply of ecosystem services. These forests store largest share (55%) of global terrestrial carbon pool. But the projected rise in temperature (4oC), CO2 levels (495 ppm) and changes in precipitation regime by 2100 are expected to cause significant changes in ecosystem productivity and nutrient turnover rate making forests more vulnerable to climate change. High temperature with low rainfall reduces tree growth, increases soil carbon fluxes by accelerating rate of nutrient cycling, restricts the range of pollinators and increases pest infestation (Phytophthora cinnamomi) affecting ecosystem health and future food security. Increase in heat waves increase the incidence of wild fires and degrade ecosystem quality. Climate change also reduces the scenic beauty, ecotourism and associated economic and mental health benefits. Proactive measures must be taken to mitigate the likely causes of climate change and efforts should be taken to conserve the existing forest reserves to ensure sustainable supply of the ecosystem services

Design and Synthesis of Chalcone Derivatives as Potent Tyrosinase Inhibitors and Their Structural Activity Relationship

Browning of fruits and vegetables is a serious issue in the food industry, as it damages the organoleptic properties of the final products. Overproduction of melanin causes aesthetic problems such as melisma, freckles and lentigo. In this study, a series of chalcones (1-10) have been synthesized and examined for their tryrosinase inhibitory activity. The results showed that flavokawain B (1), flavokawain A (2) and compound 3 were found to be potential tyrosinase inhibitors, indicating IC 14.20 -14.38 M values. This demonstrates that 4-substituted phenolic compound especially at ring A exhibited significant tyrosinase inhibition. Additionally, molecular docking results showed a strong binding affinity for compounds 1-3 through chelation between copper metal and ligands. The detailed molecular docking and SARs studies correlate well with the tyrosinase inhibition studies in vitro. The structures of these compounds were elucidated by the 1D and 2D NMR spectroscopy, mass spectrometry and single X-ray crystallographic techniques. These findings could lead to design and discovery of new tyrosinase inhibitors to control the melanine overproduction and overcome the economic loss of food industry. 5

Analysis of the Socio-Economic Conditions and Living Arrangements of Aged Widows of Rural Sindh

Abstract   This paper presents outcomes of a study that was conducted to assess myriad problems faced by old widows in rural areas of second largest province of Pakistan, Sindh. As already, there is inadequate data on the social, economic and living arrangements of aged widows of Rural Sindh. Through this research survey, gap of information on social, economic, and living arrangements of Sindhi rural aged widows is filled by primary survey data. The sample of 384 Respondents of age 60 and above was chosen by infinite population formula and respondents for collecting data were selected by using convenience sampling technique from the six rural districts of Sindh. Descriptive statistics were applied to analyze data. The results suggest that there is strong preference of son and who is considered as old age protection for aged widows, and even today residing with son is regarded as popular cultural practice in Rural Sindh. The high number of aged widows was economically dependent on their sons. Absence of old age pension, no parallel remuneration and lack of skills in aged widows are some factors which are strongly influencing and creating very severe socio-economic consequences for widows in later age. Also, because of urbanization, the extended family culture is transforming to nuclear family drastically and ultimately, it is affecting largely on the living arrangements of aged widows

Molecular Docking and Quantitative Structure Activity Relationship (QSAR) Studies of Some Newly Synthesized Poly (Azomethine) Esters

Molecular docking procedure is well known for the investigation of small molecules; however, for macromolecules, it has attained limited success so far. Thus, in an attempt, a series of poly (azomethine) esters was synthesized in a laboratory, and their model oligomer units were studied by computer-aided computational MOE software package to investigate, specifically, binding modes that could influence their anticancer activities. Poly (azomethine) ester (PAME) was prepared by solution phase polycondensation of a preformed Schiff base (SB) 4-((4-(4-(4-hydroxybenzylideneamino)phenoxy)phenylimino)methyl) phenol with terephthaloyl chloride (TC). Terpolymers (PAMEF, PAMEB, PAMESi, PAMEPr, and PAMEH) were synthesized by the incorporation of various moieties along with TC and SB in the main chain. Structural elucidation was carried out by spectroscopic studies and elemental analysis. Docking procedure, adopted to investigate anticancer activity, showed that material was docked in the same pocket of active site as by anticancer protein complex (PDB code: 1T69). Molecular docking along with the quantitative structure activity relationship (QSAR) investigations showed groove binding as a preferred mode between the material and double-stranded DNA (PDB ID-1BNA). Binding strength indicated worthy correlation with various physicochemical parameters of the material like hydrophobic surface area (Vsurf), EHOMO, ELUMO, log P, and molar refractivity (MR). Calculated values for the formation constant (Kf) showed good binding strength for polymer-DNA complex. Consequently, the synthesized material is expected to exhibit anticancer activities and could be studied further as anticancer drugs

Tumor Necrosis Factor-Alpha Gene Promoter Region Polymorphism and the Risk of Coronary Heart Disease

Background. Tumor necrosis factor-alpha (TNF-) gene polymorphisms have been implicated in the manifestation of atherosclerosis. Controversy exists regarding the link between the cytokine's variant genotype and CHD among different ethnic groups. There have been fewer studies on the TNF-gene −1031T>C and −863C>A polymorphisms in relation to CHD. Therefore, the current study was designed to investigate the association of the TNF-gene −1031T>C and −863C>A polymorphisms with CHD in a Pakistani population. Methods. Patients with CHD ( = 310) and healthy individuals ( = 310) were enrolled in this study. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results. A significant difference was observed in the −863C>A polymorphism between patients with CHD and control subjects ( < 0.0001). CHD risk was positively associated with the variant allele −863A ( < 0.0001) in the study subjects. There was no significant link between the −1031T>C polymorphism and CHD risk in the study population. Haplotypes A-T and A-C of the TNF-alpha gene loci at −863 and −1031 showed higher frequency in the patient group compared with controls ( < 0.05). Conclusion. The TNF-−863C>A gene polymorphism was associated with the pathogenesis of CHD while the −1031T>C polymorphism did not show any link with the disease in a Pakistani population

Influence of Ferrocene and Transition Metals on the Biological Activities of Schiff Bases

A series of organic and organometallic Schiff bases bearing phenylferrocene and their six transition metal complexes have been prepared and tested for their potential biological applications by using antifungal, antibacterial, antitumor activities, toxicity testing against the brine shrimp and DNA damage analysis. The copper and cobalt complexes of organic Schiff base showed significant antibacterial activity. The antifungal activities tested against six fungal strains revealed that N-(4-hydroxybenzylidene) aniline (A5) had the highest antifungal activity. Most of these compounds showed cytotoxic activity against the brine shrimp. The results of showed that these compounds had significant antitumor activity, up to 97% in the case of N-(4-chlorobenzylidene) aniline (A3). Only two compounds N-(2-hydroxy benzylidene) 4-ferrocenylaniline (F2) and Nickel (II) complex of organic Schiff base (CO2) had DNA damaging activity at 20mg/ml concentration. Validerad; 2017; Nivå 2; 2017-03-03 (andbra)</p

Effect of climatic factors on leaf litter decomposition dynamics of a subtropical scrub forest under field and microcosm conditions

This study investigated the leaf litter decomposition dynamics of Hayat-ul-Mir subtropical scrub forest in Pakistan. Litter bags were incubated for 360 days in the forest to elucidate the effect of elevation and incubation time and for 90 days in microcosms to investigate the effect of projected warming (+2.3°C and +4.5°C) and soil moisture (M15% and M20%) on litter decomposition. Site elevation significantly affected k and T50% while time affected mass loss, residual weight, remaining C and N at p < .01 in field. After 360 days of decomposition, ∼48% residual weight with 11.7 ± 0.4% of C and 1.07 ± 0.06% of N was observed in the litter bags. Higher elevations (850–1020 m) were recorded with low C and N mineralization compared to 600–850 m elevations indicating their potential for long term carbon storage. Warming (+4.5°C) significantly accelerated the pace of decomposition in microcosms with comparatively higher mass loss (+26%), k (+34%), and soil CO2 efflux (+50%) reducing T50% by 77 days than observed under ambient conditions (To). The effect of moisture was insignificant but comparatively, decomposition was high at M20%. The study concludes that future warming will significantly accelerate the pace of nutrient cycling reducing the carbon storage potential of this ecosystem

Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.Validerad;2019;Nivå 2;2019-09-18 (johcin)</p