Theoretical Analysis of Null Foley-Sammon Transform and its Implications.

Null Foley-Sammon Transform (NFST) has received increasing attention in the machine learning and pattern recognition literature. NFST finds a discriminative nullspace where all samples of the same class get mapped into a single point. It has a closed form solution and is free of parameters to tune. NFST has been leveraged in many areas including novelty detection, person or vehicle re-identification and achieved state-of-the-art results. Motivated from its attractive properties and its effectiveness in wide range of applications, in this paper we focus on the theoretical analysis of NFST. In previous literature, NFST was shown to exist in small sample size (SSS) case. We first prove that NFST can exist in non-SSS case also, under certain conditions. Thereby, we extend the domain of applicability of NFST to a more general case. Secondly, we perform analysis of the singular points of NFST, revealing important insights on their identities and existence. Thirdly, we show the theoretical relation between NFST of SSS data and NFST of the non-SSS data obtained by PCA. Fourthly, we show that this theoretical relation can be exploited to obtain an efficient algorithm for computing NFST on high dimensional SSS data. Finally, we perform extensive experiments to validate our theoretical analysis.

COVID-19-Associated mucormycosis: Case series from a tertiary care hospital in South India.

The pandemic coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is a global health problem. COVID-19 has given rise to a number of secondary bacterial or fungal infections. During the second wave of COVID-19, India experienced an epidemic of mucormycosis in COVID-19 patients. In this paper, we discuss the clinical features, investigations and management of four patients having COVID-19-associated mucormycosis (CAM), especially rhino-orbital mucormycosis (ROM) caused by Rhizopus arrhizus and Mucor species. We also compare the cases and their risk factors with previously reported CAM cases in India. Three patients had mucormycosis after recovering from COVID-19. They were successfully treated with surgical debridement and early initiation of anti-fungal therapy with systemic amphotericin B and other supportive measures such as broad-spectrum antibiotics, insulin infusion, antihypertensives and analgesics. The remaining patient had mucormycosis during COVID-19. He was admitted in the intensive care unit due to COVID-pneumonia and was on mechanical ventilation. In spite of all supportive measures, the patient succumbed to death due to cardiogenic shock. Three out of our four patients had diabetes mellitus. All patients were treated with systemic steroid during COVID-19 treatment. Diabetes mellitus and steroid treatment are the major risk factors for CAM. Early diagnosis of this life-threatening infection along with strict control of hyperglycemia is necessary for optimal treatment and better outcomes.

Platelet-Rich Plasma Ameliorates Monosodium Iodoacetate-Induced Ankle Osteoarthritis in the Rat Model via Suppression of Inflammation and Oxidative Stress.

Until now, there is no treatment that cause complete cure of the chronic inflammatory and degenerative disease, osteoarthritis (OA). Moreover, the underlying mechanisms of OA development and progress are not fully elucidated, and the present pharmacological treatment alternatives are restricted and associated with adverse side effects. Thus, the present study was conducted to evaluate the role of platelet-rich plasma (PRP) in the remedy of OA in the rat model in terms of inflammation, ankle histopathological alterations, and oxidative stress. OA was induced in male Wistar rats by injection of MIA (2 mg)/50 µL isotonic saline in the right ankle joint for two successive days in each rat. After the 2nd MIA injection, the osteoarthritic rats were allocated into two groups such as the MIA group (group 2) and MIA + PRP group (group 3). The MIA + PRP group was treated with PRP (50 µL) by injection into the ankle joint of the right hind limb of each rat at days 14, 21, and 28 after the 2nd injection of MIA. The same equivalent volume of saline, as a substitute of PRP, was injected into the ankle joint of each rat of the normal control group (group 1) and MIA group (group 2) at the same tested periods. Swelling of joint, bodyweight, total leucocytes count (TLC), and morphological as well as histological changes of ankle joints were evaluated. Serum lipid peroxides (LPO), glutathione (GSH), and glutathione S-transferase (GST) levels were examined as biomarkers of oxidative stress. Serum tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), and interleukin-4 (IL-4) were investigated by ELISA as biomarkers of inflammation. In addition, magnetic resonance imaging (MRI) was carried out to investigate the soft tissues in joints. The obtained results revealed that PRP reduced LPO and increased GSH and GST levels in osteoarthritic rats. Also, PRP significantly diminished serum TNF-α and IL-17 levels, while it increased IL-4 serum levels in rats with MIA-induced OA. Morphological observations, histological analysis, and MRI revealed a gradual diminishing in joint inflammation and destruction of cartilage in PRP-injected osteoarthritic rats. Based on these results, it can be suggested that PRP has antiarthritic potential in MIA-induced OA, which may be mediated via suppression of inflammation and oxidative stress.

Effect of paricalcitol on pancreatic oxidative stress, inflammatory markers, and glycemic status in diabetic rats.

OBJECTIVES: This study is designed to explore the effect of paricalcitol (vitamin D receptor agonist) on pancreatic oxidative stress, inflammatory markers, and adiponectin and glycemic status in diabetic rats. MATERIALS AND METHODS: Forty Sprague-Dawley male rats aged 10-12 weeks (150-250 g) were used in this study. Type 2 diabetes was developed by providing 4 weeks of high-fat-diet feeding before one shot of streptozotocin injection (40 mg/kg i.p.). Four study groups were designed as normal control rats, diabetic control vehicle-treated, diabetic paricalcitol-treated (0.8 µg/kg), and diabetic glibenclamide-treated (0.6 mg/kg) groups with 10 animals in each. After treatment of diabetic rats for 3 months, pancreatic inflammatory and oxidative stress markers, plasma adiponectin, glycemic status parameters, and histopathological pancreatic islet changes were evaluated. RESULTS: Paricalcitol and glibenclamide treatment significantly (P < 0.05) decreased plasma glucose, insulin resistance, and pancreatic malondialdehyde and tumor necrosis factor-α levels. Moreover, they significantly (P < 0.05) increased plasma fasting insulin, C-peptide, adiponectin, pancreatic IL-2, catalase, superoxide dismutase, glutathione peroxidase, and reduced glutathione when contrasted with diabetic control rats. Furthermore, they prevented extensive histopathological damage in the pancreas of diabetic rats. CONCLUSIONS: Paricalcitol reduced pancreatic oxidative stress and inflammatory markers, and improved glycemic status in diabetic rats.

Evaluation of aural manifestations in temporo-mandibular joint dysfunction.

Thirty patients with temporo-mandibular joint dysfunction were selected to investigate the changes in otoacoustic emissions before and after conservative treatment of their temporo-mandibular joints. Pure tone audiometry, transient-evoked otoacoustic emissions (TEOAE), distortion-product otoacoustic emissions (DPOAE) as well as a tinnitus questionnaire were administered to all patients before and after therapy. Therapy was conservative in the form of counselling, physiotherapy, anti-inflammatory agents, muscle relaxants, and occlusal splints. Results indicated insignificant changes in the TEOAEs, whereas there were significant increases in distortion product levels at most of the frequency bands. These results were paralleled to subjective improvement of tinnitus.

Mutagenic and cytotoxic effectiveness of diisopropyl xanthogen polysulphide in human lymphocyte cultures.

The mutagenic and cytotoxic effectiveness of the new rubber vulcanisation accelerator diisopropyl xanthogen polysulphide (Robac AS 100) was tested in human lymphocyte cultures of four healthy probands. The concentrations of Robac AS 100 were 0.57, 5.7 and 57.0 microg/ml. Higher concentrations showed too high cytotoxicity to be evaluable. Without external activation, incubation time with Robac AS 100 was 21 h. In the presence of rat liver microsomes from aroclor-induced rats (2mg microsomal protein/ml), incubation of the test compound was 2h. Mutagenicity testing was performed by analysis of micronuclei (MN), structural chromosome aberrations (CAs) and sister chromatid exchanges (SCEs). The MN-rate was determined using the cytochalasin B (cyt B) block method. For evaluation of cytotoxicity, mitotic index (MI) and nuclear division index (NDI) were determined. The validity of the test methods was ascertained by positive controls: mitomycin C (MMC) and bleomycin (BLM) were used in experiments without exogenous activation and cyclophosphamide (CP) in experiments with exogenous activation. The presence of rat liver microsomes increased the mutagenic effect of Robac AS 100 in the SCE- and MN-test. But only the highest Robac AS 100-concentration (57.0 microg/ml) showed significantly increased mutagenic activity in all tests. However, cytotoxicity at this concentration was already substantial. Therefore, we consider the evidence for mutagenicity of Robac AS 100 as limited.

Ammonia chemical ionization tandem mass spectrometry in structural determination of alkaloids. II. Tetraponerines from pseudomyrmecine ants.

Chemical ionization tandem mass spectrometry (CI-MS/MS) of alkaloids with ammonia reagent gas and collision-activated dissociation as well as EI-MS/MS were applied to the tetraponerine alkaloids in extracts from six pseudomyrmecine ants of the genus Tetraponera. The MS/MS techniques along with gas chromatography Fourier transform infrared (GC/FTIR) spectra allowed identification in two extracts of seven of the eight known tetraponerines. The EI-MS/MS fragmentations proved diagnostic for the ring system and the CI-MS/MS patterns for the C-8 or C-9 substitution, while the Bohlmann bands in FTIR spectra were diagnostic for the C-8 or C-9 configurations. An Indian ant (T. allaborans) had T-2, T-4 and T-8, while a Chinese ant (T. binghami) had T-5, T-6, T-7 and T-8. Four other ants, T. rufonigra (India), T. penzigi (Africa), T. clypeata (Africa) and T. sp. cf. emeryi (Africa), had no tetraponerines.

Novel pyrrolidines in the venom of the ant Monomorium indicum.

New 2,5-dialkylpyrrolidines found in the venom of Monomorium indicum include trans-2-butyl-5-(4-pentenyl)pyrrolidine [1], trans-2-butyl-5-(6-heptenyl)pyrrolidine [4], trans-5-(5-hexenyl)-2-(4-pentenyl)pyrrolidine [6], trans-5-(6-heptenyl)-2-(5-hexenyl)pyrrolidine [8], and trans-5-heptyl-2-hexylpyrrolidine [16], whose structures were confirmed by synthesis. The concomitance of five previously reported trans-2,5-dialkyl-pyrrolidines along with small amounts of the cis isomers and N-methyl analogues makes the venom of M. indicum the most qualitatively diverse blend of alkaloids reported from an ant to date. The toxicities to termites of four of these alkaloids were determined.

A study on fungal radioresistance and sensitivity.

Lower doses of gamma and X-rays (5 and 1 Krad, respectively) stimulated the spore germination and growth of 7 tested fungi. Higher doses (500 and 100 Krad, respectively) revealed that Epicoccum nigrum was the most radioresistant, while Alternaria humicola, Stemphylium verruculosum, Rhizopus nigricans, and Cladosporium herbarum were of moderate resistance. Aspergillus niger and Penicillium oxalicum were the most radiosensitive. Protein and polysaccharide synthesis were inhibited in the mycelium developed from irradiated spores; the inhibition was a function of dose. Study of the different factors (morphological, biological, and biochemical) indicates that variability in fungal resistance to ionizing radiation is, most probably, an inherent character, connected with mycelial water content and the natural production of a chemical substance(s) that acts as a radioprotector(s).

Stomach motility in insulin-treated sheep.

The effect of insulin-induced hypoglycaemia on the motility of the reticulum, rumen and abomasum of sheep was investigated using small lightly inflated balloons connected to transducers and a multichannel recorder. The principle response recorded was an inhibition of reticulo-ruminal and abomasal motility, occurring in 'resting' cycles only, and not during eating or rumination. The only hypermotility recorded was that shown by the abomasum just before the onset of inhibition. Ruminating cycles were recorded as frequently during hypoglycaemia as in control periods, and showed no abnormality. The inhibition was reversed by intravenous glucose or adrenaline and by feeding or ruminating.

Possible role of solar radiation on the viability of some air fungi in Egypt.

The high occurrence of Alternaria humicola and the moderate occurrence of Stemphylium verruculosum, Rhizopus nigricans, and Epicoccum nigrum in the air of Egypt could be correlated to their apparent resistance to solar radiation. Cladosporium herbarum, Aspergillus niger, and Penicillium oxalicum, although highly occurring, were light-sensitive. The miniumum solar radiation in November, coupled with the highest total fungal catch, dominated by Cladosporium herbarum, reveals the importance of solar radiation as a factor with direct effect on the air fungal population.