Hymenopteran parasitoid complex and fall armyworm: a case study in eastern India

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) has significantly affected maize crop yields, production efficiency, and farmers' incomes in the Indian Eastern Gangetic Plains region since it was first observed in India in 2018. A lack of awareness by maize growers of the appropriate selection, method, and timing of insecticide application not only creates a barrier to sustainable FAW control but also contributes to increased environmental pollution, reduced human health and increased production costs. We demonstrated that FAW inflicted the most damage in early whorl growth stage of maize, regardless of whether chemical insecticides were applied. FAW egg masses and larvae collected from maize fields in which no insecticides had been sprayed showed high parasitism rates by parasitoid wasps; in contrast fields that had been sprayed had much lower rates of parasitism on FAW. Ten hymenopteran parasitoids were observed in maize fields across the study region, suggesting a diversity of natural methods to suppress FAW in maize at different growth stages. These included two FAW egg parasitoids and eight FAW larval parasitoids. Microplitis manilae Ashmead was the most abundant FAW larval parasitoid species, and Telenomus cf. remus was the dominant FAW egg parasitoid species. Endemic FAW parasitoids such as those observed in this study have great potential as part of a sustainable, cost-effective agroecological management strategy, which can be integrated with other methods to achieve effective control of FAW.

Light-to-Heat Conversion of Optically Trapped Hot Brownian Particles

Anisotropic hybrid nanostructures stand out as promising therapeutic agents in photothermal conversion-based treatments. Accordingly, understanding local heat generation mediated by light-to-heat conversion of absorbing multicomponent nanoparticles at the single-particle level has forthwith become a subject of broad and current interest. Nonetheless, evaluating reliable temperature profiles around a single trapped nanoparticle is challenging from all of the experimental, computational, and fundamental viewpoints. Committed to filling this gap, the heat generation of an anisotropic hybrid nanostructure is explored by means of two different experimental approaches from which the local temperature is measured in a direct or indirect way, all in the context of hot Brownian motion theory. The results were compared with analytical results supported by the numerical computation of the wavelength-dependent absorption efficiencies in the discrete dipole approximation for scattering calculations, which has been extended to inhomogeneous nanostructures. Overall, we provide a consistent and comprehensive view of the heat generation in optical traps of highly absorbing particles from the viewpoint of the hot Brownian motion theory.

Angle-resolved plasmonic photocapacitance of gold nanorod dimers

The assembly of nanostructures with plausible statistical orientations has provided the opportunity to correlate physical observables to develop a diverse range of niche applications. The dimeric configurations of gold nanorods have been chosen as atypical model systems to correlate optoelectronic with mechanical properties at a number of combinations of angular orientations. Metals are considered as conductors in electronics and reflectors in optics - therefore, metallic particles at the nanoscale exhibit unique optoelectronic characteristics that enable the design of materials to meet the demand of the modern world. Gold nanorods have often been adopted as prototypical anisotropic nanostructures owing to their excellent shape-selective plasmonic tunability in the vis-NIR region. When a pair of metallic nanostructures is sufficiently close to exhibit electromagnetic interaction, the evolution of collective plasmon modes, substantial enhancement of the near-field and strong squeezing of the electromagnetic energy at the interparticle spatial region of the dimeric nanostructures occur. The localised surface plasmon resonance energies of the nanostructured dimers strongly depend on the geometry as well as the relative configurations of the neighbouring particle pairs. Recent advances in the 'tips and tricks' guide have even made it possible to assemble anisotropic nanostructures in a colloidal dispersion. The optoelectronic characteristics of gold nanorod homodimers at different mutual orientations with statistical variation of the angle between 0 and 90° at particular interparticle distances have been elucidated from both theoretical and experimental perspectives. It has been observed that the optoelectronic properties are governed by mechanical aspects of the nanorods at different angular orientations of the dimers. Therefore, we have approached the design of an optoelectronic landscape through the correlation of the plasmonics and photocapacitance through the optical torque of gold nanorod dimers.

Photothermal Reshaping of One-Dimensional Plasmonic Polymers: From Colloidal Dispersion to Living Cells

Cellular internalization of plasmonic metal nanostructured materials has recently become a requisite for biomedical engineering of several intracellular processes that could foster an extensive paradigm to perform desired functions in the living cells. While numerous anisotropic metal nanostructures can be employed to pursue the specific functions, their incorporation becomes restricted due to morphological specificity to be engulfed in the cells. Due to recent advent in the self-assembly strategies, individual gold nanospheres could be interdigitated to one-dimensional plasmonic polymers and undergo subsequent laser-induced photothermal reshaping to rod-like nanostructures. The salient feature of biological significance is merely the variation of particle size within the polymers that engenders a dramatic impact on the radiative and nonradiative properties expressed in the scale of Faraday number (F _a) and Joule number (J ₀), respectively, as a function of the aspect ratio (α) of the nanorods. The effect on the nonradiative properties augments designing of nanoscale thermometry essential for photothermal applications in living cells. The conception of the colloidal dispersion has been extended to the cellular environment in a mice model; the selective accumulation of the nanostructures in the cells could provide an invading relationship between plasmonic characteristics, temperature distribution, and the biological issues. The critical correlation between optical and thermal characteristics toward biomedical manipulation from both theoretical and experimental perspectives could augment a milestone toward the progress of modern medical sciences.

Plasmonic Sensing: Connecting the Dots

Plasmonic sensitivity of noble metals has often been attributed to the morphology of the nanostructures and dielectric effects of both the materials and the surrounding medium. The measurable plasmonic shift with respect to the change in local dielectric as a function of analyte concentrations within nanoscale volume forms the basis of plasmonic sensing. However, the situation of the surrounding medium in the presence of multicomponent systems and, moreover, inhomogeneous adsorption around the anisotropic nanostructures become seemingly complicated as the precise description of several individual components becomes nearly impossible. Therefore, we have designed a retrospective formalism through a critical condensation of the electromagnetic scattering theories, macroscopic mixing rules, and micromechanics at the metal-analyte interface that can be adopted as generalized model irrespective of morphology of the nanostructures and the nature of analytes to account for the response of all the individual (microscopic) components to the observed (macroscopic) plasmonic sensing.

Human responses to nature- and culture-based non-clinical interventions: a systematised review

AIMS

A wide range of non-clinical nature- and culture-based interventions for the treatment of health issues have been evaluated in evidence and systematic reviews. However, common outcomes of these interventions have not been identified and neuro-bio-psychosocial mechanisms underlying how these interventions impact health are not well understood. We conducted a systematised review and compared the evidence for human responses to nature- and culture-based non-clinical interventions for a range of health issues and assessed the proposed mechanisms and conceptual frameworks underlying these interventions.

METHODS

Comprehensive searches were conducted up to May 2018 in six bibliographic databases: Campbell Collaboration, Cochrane Library, Embase, Medline, Scopus and Web of Science. Studies included were evidence reviews or systematic reviews on any nature- or culture-based non-clinical intervention to improve the health of individuals.

RESULTS

A total of 60 reviews were included (33 of nature, 26 of culture, 1 of both) covering 1480 individual studies and trials. The most common review types were systematic (32), literature (22) and meta-analyses (6). Positive effects on mental health were reported for the majority of interventions, while other health outcomes such as immunity were not well represented in the review literature. A range of secondary outcomes were common to both nature- and culture-based interventions including psychological and emotional impacts, social interaction and relationship development, skills development, physical health benefits, and positive impact of the intervention environment. Only two reviews proposed conceptual frameworks, and the neuro-bio-psychosocial mechanisms that underpin the health changes were not clarified.

CONCLUSION

Future research should focus on reviewing the evidence gaps for non-clinical nature- and culture-based interventions with an emphasis on implementing larger sample sizes, cohort and longitudinal studies, which deploy a wider range of mixed-methods, quasi-experimental and randomised control trials. There should also be agreement on terminology and developing conceptual frameworks to better understand the neuro-bio-psychosocial mechanisms underlying interventions.

Manipulating the confinement of electromagnetic field in size-specific gold nanoparticles dimers and trimers

Confinement of the electromagnetic field in gold nanoparticle dimers and trimers with variations in the interparticle distances and angles has been calculated.

Pattern of nontyphoid ileal perforation over three decades in Pondicherry

Two hundred and twelve cases of ileal perforation due to different causes (excluding typhoid) were treated in 3 phases in the Department of Surgery, JIPMER Hospital, Pondicherry, during the periods 1966-78 (phase I), 1981-88 (phase II) and 1990-1998 (Phase III). Forty per cent of the patients were in the second and third decades of life. Male-to-female ratio was 2.2:1. The majority of the perforations (52.8%) were due to non-specific causes. Trauma (19.3%) and mechanical factors (12.7%) were the other principal aetiologies. Pain abdomen (92.3%), constipation (63.6%) and fever (44.3%) were the principal presenting features. Abdominal guarding and rigidity (89%) were the main physical signs. Pneumoperitoneum was present in 66.8% of cases on plain X-ray abdomen. Widal and blood culture for Salmonella typhi were negative in all. Laparotomy was done in most of the cases after adequate resuscitation. Simple closure of the perforation, wedge resection and resection anastomosis were the different procedures of management. Histology of the margin of perforation/excised gut gave added evidence of a non-typhoid etiology. Broad-spectrum antibiotics in different combinations with metronidazole were administered postoperatively. Mortality was 28.2% in Phase I, and 9.4% and 11.9% in phases II and III respectively. The lag period (advent of symptoms and hospitalization) showed definite relationship with mortality and morbidity. Wound infection, wound dehiscence, enterocutaneous fistula and septicaemia were the principal postoperative complications.

Herniation through triple defects of the diaphragm with gastric volvulus

A rare case of herniation through triple defects in the diaphragm with volvulus of the stomach is reported. Herniation with gastric volvulus was diagnosed preoperatively. Three diaphragmatic defects were detected at surgery. Repair of the defects after reduction of the abdominal contents resulted in an uneventful recovery.

Changing trends in outcome of typhoid ileal perforations over three decades in Pondicherry

Two hundred and forty eight cases of proved typhoid ileal perforation were admitted and treated in three phases in the department of surgery during 1966-1998. Of these, 71% patients belonged to second and third decades of life. Male female ratio was 4:1. Abdominal pain (100%) fever (95%) and constipation (87%) were the main presenting symptoms. Abdominal guarding and rigidity (84%) were the principal physical signs. Plain radiograph of abdomen showed evidence of pneumoperitoneum in 57% of cases. The Widal test was positive for S. typhi in 74% of cases. Blood and bone marrow culture were positive for S. typhi in 9% and 30% respectively. Histology of the excised edges of perforation confirmed typhoid pathology in 62% of specimens. Many of the patients were treated conservatively in the first phase. In phase two and three vigorous resuscitation and early surgery was resorted to. Simple closure in two layers and wedge resection were the treatment of choice in most of the cases. Bypass, ileostomy and resection were done on few occasions. Chloramphenicol was the only drug used in the first phase. Other broad spectrum antibiotics were added to chloramphenicol with metranidazole in the second phase. Ciprofloxacin and metronidazole were the drugs of choice in the third phase. The mortality rate showed a dramatic improvement from 47.2% (first phase) to 17.7% (second phase) and as low as 7% in the last phase. The lag period (advent of symptoms to time of admission to hospital) showed definite correlation with mortality. Septicemia, wound infection, dehiscence, enterocutaneous fistula were the principal postoperative complications.

Volvulus of stomach in childhood

Six children, aged upto one year, with volvulus of the stomach are reported. Vomiting and regurgitation of feeds were the main presenting symptoms. Eventration of the left hemidiaphragm was present in four cases. Barium meal confirmed the diagnosis. Five cases were operated on through an abdominal approach. Plication of the diaphragm (3 cases), colonic displacement (2) and gastrostomy (3) were resorted to. One child needed reoperation for a missed Ladd's band. There was no operative mortality.

Intrauterine perineal tear: a rare birth injury

A rare case of birth injury having intrauterine complete perineal tear is presented. Defunctioning sigmoid colostomy was undertaken because of bad perineal condition. The baby died of Pseudomonas septicemia on the 15th day before definitive surgical procedure could be undertaken.

Intestinal injuries in childhood: analysis of 32 cases

This is a retrospective study of 32 cases of intestinal injuries sustained among 135 children admitted from cases of abdominal trauma in 1976 till 1989. Falls from height or bullock cart and bull-gore injury formed the majority of the cases (21/32; 65%). Clinical thermometer accounted for perforating injuries in 2 neonates. Penetrating injury accounted for 10 cases and blunt trauma was responsible in 19. The site of injury was duodenum 1, jejunum 8, ileum 17, colon 3, rectum 4, and multiple sites 1. Associated injuries included diaphragmatic rupture 1, liver 1, mesentery 4, retroperitoneal hematoma 4, head injury 2, and loss of hand due to blast 1. Diagnosis was made on history, physical examination, pneumoperitoneum in plain x-ray, and diagnostic four-quadrant peritoneal tap. Closure of perforations was done in 21 cases, wedge resection in 3, and resection anastomosis in 5. Protective colostomy had to be done in 5 cases. Four patients died of septicemia (2) and head injury (2).

A new technique of prolapse-free transverse colostomy

With this technique, the colostomy loop emerges in the space between the linea alba and the right rectus muscle. These two tough structures act as gatekeepers and prevent prolapse of the intestine when there is a rise in the intra-abdominal pressure. The stoma is matured immediately. Small incisions and precision with the technique are essential in neonates.

Single layer abdominal wound closure in children

A single layer closure of abdominal incisions was done, including the skin, musculo-aponeurotic layer and peritoneum, with a modified 'figure-of-eight' technique, using thick monofilament nylon interrupted sutures. This technique leaves no suture material in the wound after suture removal on the 14th postoperative day. One hundred and fifty-two transverse incisions of the abdomen in children of all ages were analysed. Easy closure in difficult cases, no wound dehiscence and a greatly reduced infection rate are the advantages. We recommend this technique as a routine, particularly in poor risk patients, contaminated wounds and closure of colostomy wounds.

Subcutaneous phycomycosis from Pondicherry, South India

Four cases of subcutaneous phycomycosis diagnosed by isolating Basidiobolus meristosorus from affected tissue, are reported along with the growth characters and morphological features of this fungus. This is the first report from Pondicherry, South India where it was it was possible to isolate the causative fungus from each case.