Outbreak of severe community-acquired bacterial infections among children in North Rhine-Westphalia (Germany), October to December 2022.

PURPOSE: In late 2022, a surge of severe S. pyogenes infections was reported in several European countries. This study assessed hospitalizations and disease severity of community-acquired bacterial infections with S. pyogenes, S. pneumoniae, N. meningitidis, and H. influenzae among children in North Rhine-Westphalia (NRW), Germany, during the last quarter of 2022 compared to long-term incidences. METHODS: Hospital cases due to bacterial infections between October and December 2022 were collected in a multicenter study (MC) from 59/62 (95%) children's hospitals in NRW and combined with surveillance data (2016-2023) from the national reference laboratories for streptococci, N. meningitidis, and H. influenzae. Overall and pathogen-specific incidence rates (IR) from January 2016 to March 2023 were estimated via capture-recapture analyses. Expected annual deaths from the studied pathogens were calculated from national death cause statistics. RESULTS: In the MC study, 153 cases with high overall disease severity were reported with pneumonia being most common (59%, n = 91). IRs of bacterial infections declined at the beginning of the COVID-19 pandemic and massively surged to unprecedented levels in late 2022 and early 2023 (overall hospitalizations 3.5-fold), with S. pyogenes and S. pneumoniae as main drivers (18-fold and threefold). Observed deaths during the study period exceeded the expected number for the entire year in NRW by far (7 vs. 0.9). DISCUSSION: The unprecedented peak of bacterial infections and deaths in late 2022 and early 2023 was caused mainly by S. pyogenes and S. pneumoniae. Improved precautionary measures are needed to attenuate future outbreaks.

Accentuated eccentric resistance training: Effects on physical performance in male and female athletes.

This study aimed to compare the effects of an accentuated eccentric training programme on physical performance between men and women. Distributed in two groups by gender, 21 male and 21 female athletes performed four sets of seven repetitions of the half-squat exercise twice per week for 6 weeks. Both groups lifted the same absolute load using a rotary inertial device. To accentuate the eccentric action, the eccentric load was twice as heavy as the concentric load. Vertical jump, sprint, and change of direction (COD) performances were measured pre- and post-intervention. To measure strength gains, vertical ground reaction forces were measured for each repetition of the entire training programme. Vertical jump improved post-intervention (MG: 33.88 ± 4.94 to 35.41 ± 4.86; FG: 20.60 ± 4.62 to 22.12 ± 4.32; p < 0.001; η2p = 0.42), while sprint (MG: 3.08 ± 0.11 to 3.07 ± 0.13; FG: 3.66 ± 0.23 to 3.64 ± 0.23) and COD (MG: 7.77 ± 0.42 to 7.61 ± 0.47; FG: 8.44 ± 0.58 to 8.38 ± 0.57) remained unchanged. Concentric and eccentric forces increased for both groups from session 1 to 4 (p < 0.001; η2p >0.39), while only peak eccentric forces increased until session 12 (p = 0.009; η2p = 0.21). In conclusion, even when men are able to produce greater forces with similar loads, accentuated eccentric RT produces similar strength and strength-related adaptations in male and female athletes.

The HGR motif is the antiangiogenic determinant of vasoinhibin: implications for a therapeutic orally active oligopeptide.

The hormone prolactin acquires antiangiogenic and antivasopermeability properties after undergoing proteolytic cleavage to vasoinhibin, an endogenous prolactin fragment of 123 or more amino acids that inhibits the action of multiple proangiogenic factors. Preclinical and clinical evidence supports the therapeutic potential of vasoinhibin against angiogenesis-related diseases including diabetic retinopathy, peripartum cardiomyopathy, rheumatoid arthritis, and cancer. However, the use of vasoinhibin in the clinic has been limited by difficulties in its production. Here, we removed this barrier to using vasoinhibin as a therapeutic agent by showing that a short linear motif of just three residues (His46-Gly47-Arg48) (HGR) is the functional determinant of vasoinhibin. The HGR motif is conserved throughout evolution, its mutation led to vasoinhibin loss of function, and oligopeptides containing this sequence inhibited angiogenesis and vasopermeability with the same potency as whole vasoinhibin. Furthermore, the oral administration of an optimized cyclic retro-inverse vasoinhibin heptapeptide containing HGR inhibited melanoma tumor growth and vascularization in mice and exhibited equal or higher antiangiogenic potency than other antiangiogenic molecules currently used as anti-cancer drugs in the clinic. Finally, by unveiling the mechanism that obscures the HGR motif in prolactin, we anticipate the development of vasoinhibin-specific antibodies to solve the on-going challenge of measuring endogenous vasoinhibin levels for diagnostic and interventional purposes, the design of vasoinhibin antagonists for managing insufficient angiogenesis, and the identification of putative therapeutic proteins containing HGR.

Frequency of Polyautoimmunity in Patients With Rheumatoid Arthritis and Systemic Lupus Erythematosus.

OBJECTIVE: To describe the frequency of polyautoimmunity and multiple autoimmune syndrome in patients with rheumatoid arthritis (RA) and patients with systemic lupus erythematosus (SLE). PATIENTS AND METHODS: This was a cross-sectional observational study of patients with RA, SLE, and controls without autoimmune rheumatic disease. Cases were those with RA according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria and SLE according to the 2019 American College of Rheumatology/European League Against Rheumatism criteria, consecutively recruited in a rheumatology clinic. Controls were subjects with no rheumatic autoimmune disease (AIDs) recruited in the same area. Patients filled out a questionnaire on polyautoimmunity. Variables of interest were polyautoimmunity (RA or SLE with other AIDs), whereas secondary variables were rheumatic, skin, endocrine, digestive, and neurological AIDs. Multiple autoimmune syndrome is defined as the presence of 3 or more AIDs and a family history of AIDs. Statistical analyses performed were descriptive, bivariate, and multivariate (dependent variable: polyautoimmunity). RESULTS: The study population comprised 109 patients with RA, 105 patients with SLE, and 88 controls. Polyautoimmunity was recorded in 15 patients with RA (13.8%), 43 with SLE (41%), and 2 controls (2.2%). The most frequent AID in RA was Sjögren syndrome (53.3%), followed by Hashimoto thyroiditis and psoriasis; the most frequent AIDs in SLE were Sjögren syndrome (55.8%) and antiphospholipid syndrome (30.2%), followed by Hashimoto thyroiditis. Obesity was associated with polyautoimmunity in RA (odds ratio [OR], 3.362; p = 0.034). In SLE, joint damage (OR, 2.282; p = 0.038) and anti-RNP antibodies (OR, 5.095; p = 0.028) were risk factors for polyautoimmunity, and hydroxychloroquine was a protective factor (OR, 0.190; p = 0.004). CONCLUSIONS: Polyautoimmunity is frequent in RA and even more frequent in SLE. It was associated with obesity in RA and with joint damage and anti-RNP in SLE. Hydroxychloroquine was a protector.

Variability in the Application of Eccentric Force Using Different Rotary Inertia Devices May Influence the Treatment of Tendinopathy.

High intraset variability has been considered as a potential aid in the treatment of tendinopathy by producing forces in variable and unpredictable contexts that allow the athlete to return to sport pain free. The aim of this study was to compare the intraset variability in force profiles between different rotational inertia devices (RIDs) during concentric and eccentric (ECC) phases of movement and between different moments of inertia. Thirty-nine men performed a half-squat incremental test on 2 different RIDs: a horizontal cylinder and a vertical cone-shaped axis. Intraset variabilities in vertical force and velocity were analyzed using average coefficients of variation. RID squat exercise produced force intraset variability. The ECC phase of the movement showed more intraset variability in force output than the concentric phase. ECC vertical cone-shaped shaft showed a higher intraset variability in force than ECC horizontal cylinder-shaped shaft. This study demonstrated that using an RID to provide resistance in squat training of athletes produced a high intraset variability in the application of force.

Glucocorticoids rapidly activate cAMP production via Gαs to initiate non-genomic signaling that contributes to one-third of their canonical genomic effects.

Glucocorticoids are widely used for the suppression of inflammation, but evidence is growing that they can have rapid, non-genomic actions that have been unappreciated. Diverse cell signaling effects have been reported for glucocorticoids, leading us to hypothesize that glucocorticoids alone can swiftly increase the 3',5'-cyclic adenosine monophosphate (cAMP) production. We found that prednisone, fluticasone, budesonide, and progesterone each increased cAMP levels within 3 minutes without phosphodiesterase inhibitors by measuring real-time cAMP dynamics using the cAMP difference detector in situ assay in a variety of immortalized cell lines and primary human airway smooth muscle (HASM) cells. A membrane- impermeable glucocorticoid showed similarly rapid stimulation of cAMP, implying that responses are initiated at the cell surface. siRNA knockdown of Gαs virtually eliminated glucocorticoid-stimulated cAMP responses, suggesting that these drugs activate the cAMP production via a G protein-coupled receptor. Estradiol had small effects on cAMP levels but G protein estrogen receptor antagonists had little effect on responses to any of the glucocorticoids tested. The genomic and non-genomic actions of budesonide were analyzed by RNA-Seq analysis of 24 hours treated HASM, with and without knockdown of Gαs . A 140-gene budesonide signature was identified, of which 48 genes represent a non-genomic signature that requires Gαs signaling. Collectively, this non-genomic cAMP signaling modality contributes to one-third of the gene expression changes induced by glucocorticoid treatment and shifts the view of how this important class of drugs exerts its effects.

Preterm children's long-term academic performance after adaptive computerized training: an efficacy and process analysis of a randomized controlled trial.

BACKGROUND: Adaptive computerized interventions may help improve preterm children's academic success, but randomized trials are rare. We tested whether a math training (XtraMath®) versus an active control condition (Cogmed®; working memory) improved school performance. Training feasibility was also evaluated. METHODS: Preterm born first graders, N = 65 (28-35 + 6 weeks gestation) were recruited into a prospective randomized controlled multicenter trial and received one of two computerized trainings at home for 5 weeks. Teachers rated academic performance in math, reading/writing, and attention compared to classmates before (baseline), directly after (post), and 12 months after the intervention (follow-up). Total academic performance growth was calculated as change from baseline (hierarchically ordered-post test first, follow-up second). RESULTS: Bootstrapped linear regressions showed that academic growth to post test was significantly higher in the math intervention group (B = 0.25 [95% confidence interval: 0.04-0.50], p = 0.039), but this difference was not sustained at the 12-month follow-up (B = 0.00 [-0.31 to 0.34], p = 0.996). Parents in the XtraMath group reported higher acceptance compared with the Cogmed group (mean difference: -0.49, [-0.90 to -0.08], p = 0.037). CONCLUSIONS: Our findings do not show a sustained difference in efficacy between both trainings. Studies of math intervention effectiveness for preterm school-aged children are warranted. IMPACT: Adaptive computerized math training may help improve preterm children's short-term school performance. Computerized math training provides a novel avenue towards intervention after preterm birth. Well-powered randomized controlled studies of math intervention effectiveness for preterm school-aged children are warranted.

Predicting Loading Intensity Measuring Velocity in Barbell Hip Thrust Exercise.

ABSTRACT: de Hoyo, M, Núñez, FJ, Sañudo, B, Gonzalo-Skok, O, Muñoz-López, A, Romero-Boza, S, Otero-Esquina, C, Sánchez, H, and Nimphius, S. Predicting loading intensity measuring velocity in barbell hip thrust exercise. J Strength Cond Res 35(8): 2075-2081, 2021-The barbell hip thrust is an increasingly used exercise to target the hip extensors. Direct and indirect measurement of 1 repetition maximum (1RM) to determine the relative load of each exercise is time-consuming; therefore, practitioners may be more in favor of monitoring velocity and determining relative load through velocity-based prediction models for an exercise. This study aimed to assess the relationship between mean velocity (MV) and mean propulsive velocity (MPV) at different relative training loads (%1RM) in the barbell hip thrust exercise. One hundred two male sport science students performed an incremental 1RM testing protocol for the barbell hip thrust exercise, and a linear position transducer measured MV and MPV of the barbell. The 1RM was reached at 0.25 ± 0.03 m·s-1, and the regression model generated to estimate a relative load showed an acceptable standard error of estimate (7.01 ± 1.05% 1RM and 7.36 ± 1.05% 1RM for MV and MPV, respectively) with a very large explained variance (R2 = 0.94). These results may have important practical applications for the prescription and monitoring of the accessory exercise of the hip thrust for monitoring training load and predicting 1RM without undertaking a RM test.

Establishment, spread and early impacts of the first biocontrol agent against an invasive plant in continental Europe.

Classical biocontrol is key for the successful management of invasive alien plants; yet, it is still relatively new in Europe. Although post-release monitoring is essential to evaluate the effectiveness of a biocontrol agent, it is often neglected. This study reports the detailed post-release monitoring of the first biocontrol agent intentionally introduced against an invasive plant in continental Europe. The Australian bud-galling wasp Trichilogaster acaciaelongifoliae (Frogatt) is used to control the invasive Acacia longifolia (Andr.) Willd., with a long history of success in South Africa. This biocontrol agent was first released in Europe in 2015 at several sites along the Portuguese coast. We monitored the establishment, spread and early impacts of T. acaciaelongifoliae on target-plants in Portugal, across 61 sites, from 2015 to 2020. Initial release of adults emerging from galls imported from South Africa and the subsequent releases from galls established in Portugal (2018 onwards) was compared, assessing the implications of the hemisphere shift. The impacts on the reproductive output and vegetative growth of A. longifolia were evaluated in more detail at three sites. From 2015 to 2019, 3567 T. acaciaelongifoliae were released at 61 sites, with establishment confirmed at 36 sites by 2020. The transfer of the wasp from the southern hemisphere limited its initial establishment, but increased rates of establishment followed with synchronization of its life cycle with northern hemisphere conditions. Therefore, after an initial moderate establishment, T. acaciaelongifoliae adapted to the northern hemisphere conditions and experienced an exponential growth (from 66 galls by 2016, to 24000 galls by 2018). Galled A. longifolia branches produced significantly fewer pods (-84.1%), seeds (-95.2%) and secondary branches (-33.3%) and had fewer phyllodes but increased growth of the main branch compared to ungalled branches. Trichilogaster acaciaelongifoliae successfully established in the northern hemisphere, despite the initial phenological mismatch and adverse weather conditions. To achieve this, it had to establish and synchronize its life cycle with the phenology of its host-plant, after which it developed exponentially and began to show significant impacts on the reproductive output of A. longifolia.

The use of real-time monitoring during flywheel resistance training programmes: how can we measure eccentric overload? A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to analyse the technologies and main training variables used in the literature to monitor flywheel training devices in real time. In addition, as the main research question, we investigated how eccentric overload can be effectively monitored in relation to the training variable, flywheel shaft type device and the moment of inertia selected. The initial search resulted in 11,621 articles that were filtered to twenty-eight and seventeen articles that met the inclusion criteria for the systematic review and meta-analysis, respectively. The main technologies used included force sensors and rotary/linear encoders, mainly to monitor peak or mean force, power or speed. An eccentric overload was not always achieved using flywheel devices. The eccentric overload measurement was related to the main outcome selected. While mean force (p = 0.011, ES = -0.84) and mean power (p < 0.001, ES = -0.30) favoured the concentric phase, peak power (p < 0.001, ES = 0.78) and peak speed (p < 0.001, ES = 0.37) favoured the eccentric phase. In addition, the lower moments of inertia (i.e., from 0.01 to 0.2 kg·m2) and a cylindrical shaft type (i.e., vs conical pulley) showed higher possibilities to achieve eccentric overload. A wide variety of technologies can be used to monitor flywheel devices, but to achieve eccentric overload, a flywheel cylindrical shaft type with low moments of inertia is advised to be used.

A data mining based clinical decision support system for survival in lung cancer.

BACKGROUND: A clinical decision support system (CDSS ) has been designed to predict the outcome (overall survival) by extracting and analyzing information from routine clinical activity as a complement to clinical guidelines in lung cancer patients. MATERIALS AND METHODS: Prospective multicenter data from 543 consecutive (2013-2017) lung cancer patients with 1167 variables were used for development of the CDSS. Data Mining analyses were based on the XGBoost and Generalized Linear Models algorithms. The predictions from guidelines and the CDSS proposed were compared. RESULTS: Overall, the highest (> 0.90) areas under the receiver-operating characteristics curve AUCs for predicting survival were obtained for small cell lung cancer patients. The AUCs for predicting survival using basic items included in the guidelines were mostly below 0.70 while those obtained using the CDSS were mostly above 0.70. The vast majority of comparisons between the guideline and CDSS AUCs were statistically significant (p < 0.05). For instance, using the guidelines, the AUC for predicting survival was 0.60 while the predictive power of the CDSS enhanced the AUC up to 0.84 (p = 0.0009). In terms of histology, there was only a statistically significant difference when comparing the AUCs of small cell lung cancer patients (0.96) and all lung cancer patients with longer (≥ 18 months) follow up (0.80; p < 0.001). CONCLUSIONS: The CDSS successfully showed potential for enhancing prediction of survival. The CDSS could assist physicians in formulating evidence-based management advice in patients with lung cancer, guiding an individualized discussion according to prognosis.

Transforming Growth Factor-ß1 Decreases ß2-Agonist-induced Relaxation in Human Airway Smooth Muscle.

Helper T effector cytokines implicated in asthma modulate the contractility of human airway smooth muscle (HASM) cells. We have reported recently that a profibrotic cytokine, transforming growth factor (TGF)-ß1, induces HASM cell shortening and airway hyperresponsiveness. Here, we assessed whether TGF-ß1 affects the ability of HASM cells to relax in response to ß2-agonists, a mainstay treatment for airway hyperresponsiveness in asthma. Overnight TGF-ß1 treatment significantly impaired isoproterenol (ISO)-induced relaxation of carbachol-stimulated, isolated HASM cells. This single-cell mechanical hyporesponsiveness to ISO was corroborated by sustained increases in myosin light chain phosphorylation. In TGF-ß1-treated HASM cells, ISO evoked markedly lower levels of intracellular cAMP. These attenuated cAMP levels were, in turn, restored with pharmacological and siRNA inhibition of phosphodiesterase 4 and Smad3, respectively. Most strikingly, TGF-ß1 selectively induced phosphodiesterase 4D gene expression in HASM cells in a Smad2/3-dependent manner. Together, these data suggest that TGF-ß1 decreases HASM cell ß2-agonist relaxation responses by modulating intracellular cAMP levels via a Smad2/3-dependent mechanism. Our findings further define the mechanisms underlying ß2-agonist hyporesponsiveness in asthma, and suggest TGF-ß1 as a potential therapeutic target to decrease asthma exacerbations in severe and treatment-resistant asthma.

Three-dimensional cardiac fibre disorganization as a novel parameter for ventricular arrhythmia stratification after myocardial infarction.

AIMS: Myocardial infarction (MI) alters cardiac fibre organization with unknown consequences on ventricular arrhythmia. We used diffusion tensor imaging (DTI) of three-dimensional (3D) cardiac fibres and scar reconstructions to identify the main parameters associated with ventricular arrhythmia inducibility and ventricular tachycardia (VT) features after MI. METHODS AND RESULTS: Twelve pigs with established MI and three controls underwent invasive electrophysiological characterization of ventricular arrhythmia inducibility and VT features. Animal-specific 3D scar and myocardial fibre distribution were obtained from ex vivo high-resolution contrast-enhanced T1 mapping and DTI sequences. Diffusion tensor imaging-derived parameters significantly different between healthy and scarring myocardium, scar volumes, and left ventricular ejection fraction (LVEF) were included for arrhythmia risk stratification and correlation analyses with VT features. Ventricular fibrillation (VF) was the only inducible arrhythmia in 4 out of 12 infarcted pigs and all controls. Ventricular tachycardia was also inducible in the remaining eight pigs during programmed ventricular stimulation. A DTI-based 3D fibre disorganization index (FDI) showed higher disorganization within dense scar regions of VF-only inducible pigs compared with VT inducible animals (FDI: 0.36; 0.36-0.37 vs. 0.32; 0.26-0.33, respectively, P = 0.0485). Ventricular fibrillation induction required lower programmed stimulation aggressiveness in VF-only inducible pigs than VT inducible and control animals. Neither LVEF nor scar volumes differentiated between VF and VT inducible animals. Re-entrant VT circuits were localized within areas of highly disorganized fibres. Moreover, the FDI within heterogeneous scar regions was associated with the median VT cycle length per animal (R2 = 0.5320). CONCLUSION: The amount of scar-related cardiac fibre disorganization in DTI sequences is a promising approach for ventricular arrhythmia stratification after MI.

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging.

We evaluated the dynamics of ocular surface temperature using thermal imaging in 21 glaucoma subjects and 19 healthy subjects. On opening of the eye, subjects with glaucoma showed significantly cooler temperatures in the central cornea compared to the control group. The upper eyelid was also significantly cooler just before the eye opened. Immediately after opening the eye, the dynamic of temperature change was different in the two groups. In subjects with glaucoma, the eyes cooled significantly faster, with an average decrease of 0.49°C during the first second compared to 0.24°C in the control group. Our results support the hypothesis that both the stability of the tear film and changes in the ocular blood supply in subjects with glaucoma play an important role in thermal dynamics of the ocular surface.

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging: publisher's note.

This publisher's note corrects the funding section in J. Opt. Soc. Am. A36, 1015 (2019)JOAOD61084-752910.1364/JOSAA.36.001015.

Pollination networks from natural and anthropogenic-novel communities show high structural similarity.

The Anthropocene is marked by an unprecedented homogenisation of the world's biota, confronting species that never co-occurred during their evolutionary histories. Interactions established in these novel communities may affect ecosystem functioning; however, most research has focused on the impacts of a minority of aggressive invasive species, while changes inflicted by a less conspicuous majority of non-invasive alien species on community structure are still poorly understood. This information is critical to guide conservation strategies, and instrumental to advance ecological theory, particularly to understand how non-native species integrate in recipient communities and affect the interactions of native species. We evaluated how the structure of 50 published pollination networks changes with the proportion of alien plant species and found that network structure is largely unaffected. Although some communities were heavily invaded, the proportion of alien plant species was relatively low (mean = 10%; max. = 38%). We further characterized the pollination network in a botanic garden with a plant community dominated by non-invasive alien species (85%). We show that the structure of this novel community is also not markedly different from native-dominated communities. Plant-pollinator interactions revealed no obvious differences regarding plant origin (native vs. alien) or the native bioregion of the introduced plants. This overall similarity between native and alien plants is likely driven by the contrasting patterns of invasive plants (promoting generalism), and non-invasive aliens, suggested here to promote specialization.

Differences of Medical Care for Acute Severe Viral Bronchiolitis in Two Urban Areas in Europe.

BACKGROUND: Acute viral bronchiolitis is a frequent disease in infancy. There is little knowledge on medical care of severely affected infants in different European countries. PATIENTS: Infants (n=146) with bronchiolitis requiring respiratory support in winter season 2015/2016 treated in either one of two regions in Central Europe: South of greater Paris region in France (group 1) and Ruhr area in Germany (group 2). METHODS: Retrospective chart review. Primary outcome parameter was duration of respiratory support. RESULTS: Infants in group 1 (n=96) were younger, suffered less frequently from neurologic disorders and had lower respiratory rates than in group 2 (n=50). CO2 levels and dyspnea score were similar. Ninety percent of infants in group 1 were treated by nasal Continuous Airway Pressure CPAP, while 80% of infants in group 2 were treated by High Flow Nasal Cannula HFNC. Duration of respiratory support was significantly shorter in group 1. Infants in group 2 received more frequently infusion therapy, more antibiotics and more inhalation therapy. DISCUSSION: Our results show better outcome for infants with viral bronchiolitis treated in France. Striking differences were the practice of respiratory support (nasal CPAP vs. HFNC) and the prescription of supportive treatments. CONCLUSION: Treatment approaches in severe acute viral bronchiolitis differ widely between a French and a German urban region.

Design, Synthesis, and Evaluation of Amphiphilic Cyclic and Linear Peptides Composed of Hydrophobic and Positively-Charged Amino Acids as Antibacterial Agents.

Antimicrobial peptides (AMPs) contain amphipathic structures and are derived from natural resources. AMPs have been found to be effective in treating the infections caused by antibiotic-resistant bacteria (ARB), and thus, are potential lead compounds against ARB. AMPs' physicochemical properties, such as cationic nature, amphiphilicity, and their size, will provide the opportunity to interact with membrane bilayers leading to damage and death of microorganisms. Herein, AMP analogs of [R4W4] were designed and synthesized by changing the hydrophobicity and cationic nature of the lead compound with other amino acids to provide insights into a structure-activity relationship against selected model Gram-negative and Gram-positive pathogens. Clinical resistant strains of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) were used in the studies. Our results provided information about the structural requirements for optimal activity of the [R4W4] template. When tryptophan was replaced with other hydrophobic amino acids, such as phenylalanine, tyrosine, alanine, leucine, and isoleucine, the antibacterial activities were significantly reduced with MIC values of >128 µg/mL. Furthermore, a change in stereochemistry caused by d-arginine, and use of N-methyltryptophan, resulted in a two-fold reduction of antibacterial activity. It was found that the presence of tryptophan is critical for antibacterial activity, and could not be substituted with other hydrophobic residues. The study also confirmed that cyclic peptides generally showed higher antibacterial activities when compared with the corresponding linear counterparts. Furthermore, by changing tryptophan numbers in the compound while maintaining a constant number of arginine, we determined the optimal number of tryptophan residues to be four, as shown when the number of tryptophan residues increased, a decrease in activity was observed.

Four-trophic level food webs reveal the cascading impacts of an invasive plant targeted for biocontrol.

Biological invasions are a major threat to biodiversity and as such understanding their impacts is a research priority. Ecological networks provide a valuable tool to explore such impacts at the community level, and can be particularly insightful for planning and monitoring biocontrol programmes, including the potential for their seldom evaluated indirect non-target effects. Acacia longifolia is among the worst invasive species in Portugal, and has been recently targeted for biocontrol by a highly specific gall-wasp. Here we use an ambitious replicated network approach to: (1) identify the mechanisms by which direct and indirect impacts of A. longifolia can cascade from plants to higher trophic levels, including gallers, their parasitoids and inquilines; (2) reveal the structure of the interaction networks between plants, gallers, parasitoids and inquilines before the biocontrol; and (3) explore the potential for indirect interactions among gallers, including those established with the biocontrol agent, via apparent competition. Over a 15-month period, we collected 31,737 galls from native plants and identified all emerging insects, quantifying the interactions between 219 plant-, 49 galler-, 65 parasitoid- and 87 inquiline-species-one of the largest ecological networks to date. No galls were found on any of the 16 alien plant species. Invasion by A. longifolia caused an alarming simplification of plant communities, with cascading effects to higher trophic levels, namely: a decline of overall gall biomass, and on the richness, abundance and biomass of galler insects, their parasitoids, and inquilines. Correspondingly, we detected a significant decline in the richness of interactions between plants and galls. The invasion tended to increase overall interaction evenness by promoting the local extinction of the native plants that sustained more gall species. However, highly idiosyncratic responses hindered the detection of further consistent changes in network topology. Predictions of indirect effects of the biocontrol on native gallers via apparent competition ranged from negligible to highly significant. Such scenarios are incredibly hard to predict, but even if there are risks of indirect effects it is critical to weigh them carefully against the consequences of inaction and invasive species spread.

Relationship of the drying process of a corn grain with the thermal emissivity and optical interference in the mid infrared range.

A study of the effect of the thin layer of free water in corn kernels on the emissivity and interference in the mid infrared range was performed. The emissivity was measured through thermal infrared images by direct method for 8 days, allowing observance that the thickness of free water modifies the quantity of emitted energy and emissivity; however, in the first days when the layer of free water is not optically thick the interference caused by the thin film of superficial water averts a correct measurement of the emissivity. This interference effect was studied and characterized, finding that the number of oscillations in the energy of the grain, observed and counted in a very small area, can be used to compute the thickness of the free water layer contained between the endosperm and the pericarp of the grain.