An Empirical Analysis of the Linder

This paper presents empirical evidence in support of the Linder theory of international trade for three of the South Asian countries, Bangladesh, India, and Pakistan. This finding implies that these countries trade more intensively with countries of other regions, which may have similar per capita income levels, as predicted by Linder in his hypothesis. The contribution of this research is threefold: first, there is new information on the Linder hypothesis by focusing on South Asian countries; second, this is one of very few analyses to capture both time-series and cross-section elements of the trade relationship by employing a panel data set; third, the empirical methodology used in this analysis corrects a major shortcoming in the existing literature by using a censored dependent variable in estimation.

An Empirical Analysis of the Linder Theory of International Trade for South Asian Countries.

This paper presents empirical evidence in support of the Linder theory of international trade for three of the South Asian countries, Bangladesh, India, and Pakistan. This finding implies that these countries trade more intensively with countries of other regions, which may have similar per capita income levels, as predicted by Linder in his hypothesis. The contribution of this research is threefold: first, there is new information on the Linder hypothesis by focusing on South Asian countries; second, this is one of very few analyses to capture both time-series and cross-section elements of the trade relationship by employing a panel data set; third, the empirical methodology used in this analysis corrects a major shortcoming in the existing literature by using a censored dependent variable in estimation

GIS-based distribution, population estimation, and morphological variation of Brown sand boa (Eryx johnii Russell, 1801) from Cholistan desert, Pakistan

Pakistan has a rich diversity of herpetofauna. While numerous diversity studies on snakes have been carried out in Sindh and Baluchistan regions, none exists on the Cholistan desert landscape. Therefore, we aimed to conduct a one-year study on the different microhabitats of the Cholistan desert, to estimate the distribution and density of Brown sand boa (Eryx johnii). The sampling techniques include hand-picking, pitfall traps, and opportunistic visual encounters by amateur trackers. During the present study, 36 specimens of E. johnii were recorded for the assessment of the GIS-based distribution of species from the study area. E. johnii was recorded from 20 localities in the Cholistan desert. Further, we identified five different microhabitats have been identified from the study area for population estimation and morphological variation of E. johnii. The relative abundance of males, females, and juveniles was 0.5, 0.33, and 0.6, respectively. Morphologically, the males are significantly larger and heavier than females. We recorded two types of coloration, i.e., yellowish and reddish morphs, from various habitats of the Cholistan desert. This study provides important information on the distribution and density of the Brown sand boa in the understudied Cholistan desert landscape. The current study evaluates the distribution ranges of Brown sand boa to estimate the population density for their conservation in current localities. More investigation is required to evaluate the diversity and distribution of other species in the area because the one-year study timeframe and use of amateur trackers may have produced bias in data collecting

Diversity and habitat preferences of amphibians and reptiles in Pakistan: a review

Geographical position of Pakistan is unique, and country harbors two out of six zoogeographical regions. The country can be divided into 15 habitat types in three major divisions: the mountainous region, foothills, and Indus plains. Overall, 219 species including 24 amphibians and 195 reptiles have been reported so far. Out of these, nine amphibian and 13 reptilian species are endemic to Pakistan. Despite this richness, there is paucity of knowledge regarding diversity of amphibians and reptiles as very few species have been thoroughly studied and very small area has been explored. This has led to the uncertainties regarding distribution and taxonomy of these taxa in the country. The herpetofauna is not protected by law in the country, and their conservation status is yet to be evaluated. Furthermore, distribution ranges of amphibians and reptiles have been changed and systemized survey work is required to update baseline information in the country

Molecular identification of genus Duttaphrynus from Punjab, Pakistan

The Indus valley toad and common Asian toad are widely distributed toads in Pakistan. There is doubt in the taxonomic position of species within the genus Duttaphrynus in Pakistan as most of the species identified on morphology. Previously, Bufo melanostictus hazarensis identified on morphology but during the present study, it is confirmed as Duttaphrynus melanostictus-based COI sequences (MK941836). The interspecific divergence between Duttaphrynus stomaticus and D. melanostictus was 16%. The intraspecific divergence of D. stomaticus (MK947909.1) was ranging from 0% to 1% while the intraspecific divergence of D. melanostictus (MK941836) was high ranging from 10% to 11%. Overall, genetic variation between the species of genus Duttaphrynus based on p-distance was 14%. In our recommendation, a large-scale molecular identification of amphibians should take into consideration for exact species identification to report any new species from Pakistan

Nucleotide analysis and prevalence of Escherichia coli isolated from feces of some captive avian species

The aim of the study was to check the prevalence of Escherichia coli in some captive avian species, seasonal effect on the E.coli prevalence and analysis of nucleotide sequences of E.coli. A total of 132 samples, 33 from Turkey (Meleagris gallopavo), 33 form Pheasant (Phasianus colchicus), 33 from Budgerigar (Melopsittacus undulates) and 33 from Chukar partridge (Alectoris chukar) were collected from Conservation and Research Center, UVAS, Ravi Campus, Pattoki. Colony forming units was quantified for each sample. E. coli confirmation was done by biochemical and molecular characterization. 16S rRNA was amplified and sequenced. 16S rRNA sequence was submitted to NCBI under the accession number MN841017, MN841018 and MN841019.Descriptive statistics showed the mean ± SEM value for E. coli CFU/ml of fecal sample from Turkey 1.91 × 108 ± 4.4 × 107, for Pheasants, the mean ± SEM was 1.55 × 108 ± 5.2 × 107 CFU/ml of fecal sample. The mean ± SEM of the fecal sample for Budgerigars and Chukar were 2.12 × 108 ± 3.3 × 107 CFU/ml and 1.6 × 108 ± 4.5 × 107 CFU/ml respectively. Inferential statistics showed that regardless of the bird species, there was almost a similar frequency of E. coli CFU/ml of fecal sample (p = 0.74). However, the incidence of E. coli fluctuates significantly depending on the season in the case of turkey and pheasants, and the impact was statistically significant (p < 0.0005). E.coli was most prevalent in Turkey during rainy summer and in Pheasants during cool dry winter. These findings show that accidental or direct contact with feces of these captive birds have possible risk of gastric illness to humans and animals. Furthermore, understanding the mechanisms driving the seasonality of this important zoonotic pathogen will allow for the execution of effective control strategies when it is most prevalent

Preparation and Numerical Optimization of TiO₂:CdS Thin Films in Double Perovskite Solar Cell

This work focuses on preparing TiO2, CdS, and composite TiO2:CdS thin films for photovoltaic applications by thermal evaporation. The suggested materials exhibit very good optical and electrical properties and can play a significant role in enhancing the efficiency of the device. Various microscopy and spectroscopy techniques were considered to investigate the optical, morphological, photoluminescence, and electrical properties. FTIR confirms the material identification by displaying some peaks in the fingerprint region. UV Vis spectroscopy yields high transmission (80–90%) and low absorbance (5–10%) within the spectral region from 500 nm to 800 nm for the composite thin films. The optical band gap values for CdS, TiO2, and TiO2:CdS thin films are 2.42 eV, 3.72 eV, and 3.6 eV. XRD was utilized to analyze the amorphous nature of the thin films, while optical and SEM microscopy were employed to examine the morphological changes caused by the addition of CdS to TiO2. The decrease in the bandgap of the composite thin films was determined by the Tauc plot, which is endorsed due to the band tailing effects. Photoluminescence spectroscopy depicts several emission peaks in the visible region when they are excited at different wavelengths, and the electrical measurement enhances the material conductivity. Furthermore, the proposed electron transport materials (TiO2, CdS, TiO2:CdS) were simulated with different perovskite materials to validate their design by employing the SCAPS-1D program and assess their performance in commercial implementation. The observed results suggest that TiO2:CdS is a promising candidate to be used as an ETM in PSC with enhanced productivity

Exogenously applied nicotinic acid alleviates drought stress by enhancing morpho-physiological traits and antioxidant defense mechanisms in wheat

Across the globe, the frequent occurrence of drought spells has significantly undermined the sustainability of modern high-input farming systems, particularly those focused on staple crops like wheat. To ameliorate the deleterious impacts of drought through a biologically viable and eco-friendly approach, a study was designed to explore the effect of nicotinic acid on different metabolic, and biochemical processes, growth and yield of wheat under optimal moisture and drought stress (DS). The current study was comprised of different levels of nicotinic acid applied as foliar spray (0 g L−1, 0.7368, 1.477, 2.2159 g L−1) and fertigation (0.4924, 0.9848, and 1.4773 g L−1) under normal conditions and imposed drought by withholding water at anthesis stage. The response variables were morphological traits such as roots and shoots characteristics, yield attributes, grain and biological yields along with biosynthesis of antioxidants. The results revealed that nicotinic acid dose of 2.2159 g L−1 out-performed rest of treatments under both normal and DS. The same treatment resulted in the maximum root growth (length, fresh and dry weights, surface area, diameter) and shoot traits (length, fresh and dry weights) growth. Additionally, foliar applied nicotinic acid (2.2159 g L−1) also produced as the highest spike length, grains spike−1, spikelet’s spike−1 and weight of 1000 grains. Moreover, these better yield attributes led to significantly higher grain yield and biological productivity of wheat. Likewise in terms of physiological growth of wheat under DS, the same treatment remained superior by recording the highest SPAD value, relative water content, water potential of leaves, leaf area, stomatal conductance (292 mmolm−2S−1), internal carbon dioxide concentration, photosynthesis and transpiration rate. Interestingly, exogenously applied nicotinic acid remained effective in triggering the antioxidant system of wheat by recording significantly higher catalase, peroxidase, superoxide dismutase and ascorbate peroxidase