Tag: pubmed

PLoS Comput Biol. 2022 Mar 8;18(3):e1009925. doi: 10.1371/journal.pcbi.1009925. Online ahead of print.

ABSTRACT

A central goal in sensory neuroscience is to understand the neuronal signal processing involved in the encoding of natural stimuli. A critical step towards this goal is the development of successful computational encoding models. For ganglion cells in the vertebrate retina, the development of satisfactory models for responses to natural visual scenes is an ongoing challenge. Standard models typically apply linear integration of visual stimuli over space, yet many ganglion cells are known to show nonlinear spatial integration, in particular when stimulated with contrast-reversing gratings. We here study the influence of spatial nonlinearities in the encoding of natural images by ganglion cells, using multielectrode-array recordings from isolated salamander and mouse retinas. We assess how responses to natural images depend on first- and second-order statistics of spatial patterns inside the receptive field. This leads us to a simple extension of current standard ganglion cell models. We show that taking not only the weighted average of light intensity inside the receptive field into account but also its variance over space can partly account for nonlinear integration and substantially improve response predictions of responses to novel images. For salamander ganglion cells, we find that response predictions for cell classes with large receptive fields profit most from including spatial contrast information. Finally, we demonstrate how this model framework can be used to assess the spatial scale of nonlinear integration. Our results underscore that nonlinear spatial stimulus integration translates to stimulation with natural images. Furthermore, the introduced model framework provides a simple, yet powerful extension of standard models and may serve as a benchmark for the development of more detailed models of the nonlinear structure of receptive fields.

PMID:35259159 | DOI:10.1371/journal.pcbi.1009925

PLoS One. 2022 Mar 8;17(3):e0255753. doi: 10.1371/journal.pone.0255753. eCollection 2022.

ABSTRACT

While peptides can be excellent therapeutics for several conditions, their limited in vivo half-lives have been a major bottleneck in the development of therapeutic peptides. Conjugating the peptide to an inert chemical moiety is a strategy that has repeatedly proven to be successful in extending the half-life of some therapeutics. This systematic review and meta-analysis was conducted to examine the available literature and assess it in an unbiased manner to determine which conjugates, both biological and synthetic, provide the greatest increase in therapeutic peptide half-life. Systematic searches run on PubMed, Scopus and SciFinder databases resulted in 845 studies pertaining to the topic, 16 of these were included in this review after assessment against pre-specified inclusion criteria registered on PROSPERO (#CRD42020222579). The most common reasons for exclusion were non-IV administration and large peptide size. Of the 16 studies that were included, a diverse suite of conjugates that increased half-life from 0.1 h to 33.57 h was identified. Amongst these peptides, the largest increase in half-life was seen when conjugated with glycosaminoglycans. A meta-analysis of studies that contained fatty acid conjugates indicated that acylation contributed to a statistically significant extension of half-life. Additionally, another meta-analysis followed by a sensitivity analysis suggested that conjugation with specifically engineered recombinant peptides might contribute to a more efficient extension of peptide half-life as compared to PEGylation. Moreover, we confirmed that while polyethylene glycol is a good synthetic conjugate, its chain length likely has an impact on its effectiveness in extending half-life. Furthermore, we found that most animal studies do not include as much detail when reporting findings as compared to human studies. Inclusion of additional experimental detail on aspects such as independent assessment and randomization may be an easily accomplished strategy to drive more conjugated peptides towards clinical studies.

PMID:35259149 | DOI:10.1371/journal.pone.0255753

Plast Reconstr Surg. 2022 Mar 9. doi: 10.1097/PRS.0000000000008990. Online ahead of print.

ABSTRACT

BACKGROUND: Hyaluronic acid soft-tissue augmentation fillers are commonly injected into multiple areas of the face, including the tear trough. Despite well-documented risks, there is no standardized, evidence-based approach to inject filler in this area, be it using a hypodermic needle or a microcannula. The authors, therefore, sought to establish a preference between the two methods to facilitate progression toward standardization and prevention of adverse events.

METHODS: This is a systematic review of articles discussing hyaluronic acid tear trough injection techniques performed in vivo and related outcomes. Searches were conducted across The Cochrane Library, PubMed, Scopus, Web of Science, and Embase to yield relevant articles published before February of 2020. All selected articles incorporated discrete patient cases and were analyzed by a variety of variables assessing evidence strength, outcomes, technique, and patient safety.

RESULTS: After appraisal, 42 articles met eligibility criteria: 20 using needles, 12 using cannulas, and 10 focusing on adverse events. Level III was the most commonly afforded evidence grade, corresponding to retrospective, nonexperimental descriptive studies. There were no statistically significant differences in reported aesthetic results, patient satisfaction, or incidence of adverse events across the needle-based and cannula-based articles. Some technique trends, such as targeted anatomical plane and needle position, emerged in subsequent articles.

CONCLUSION: Given that there were no statistically significant differences in patient safety or outcomes, an evidence-based preference for needle or cannula injection into the tear trough cannot be made at this time. Current inconsistencies make tear trough injection procedures difficult to replicate, making standardization based on avoidance of adverse events not feasible.

PMID:35259144 | DOI:10.1097/PRS.0000000000008990

Plast Reconstr Surg. 2022 Mar 9. doi: 10.1097/PRS.0000000000009058. Online ahead of print.

ABSTRACT

BACKGROUND: Only a few studies have directly compared outcomes of different arm contouring techniques across matched cohorts of patients. In this study, the authors present preliminary data comparing outcomes of conventional open suction-assisted brachioplasty (using the Pascal and Le Louarn procedure) versus combined liposuction/laser skin tightening in (grade 2b arm ptosis per El Khatib classification).

METHODS: Thirty patients (60 arms) (28 women, two men) with moderate brachial ptosis (severe upper arm adiposity and a moderate degree of skin laxity) (grade 2b arm ptosis per El Khatib classification) were included. Objective and subjective measures were used in the assessment of results.

RESULTS: There were no statistically significant differences in objective measurements (arm circumference reduction ratio and percentage of ptosis elimination) between the groups. Patient satisfaction scores were higher with liposuction/laser skin tightening and found to be statistically significant (p < 0.05). Patients in this latter cohort reported less pain and earlier return to work (mean less than a week) (p < 0.05). Four patients complained of residual ptosis in each group.

CONCLUSIONS: Liposuction/laser skin tightening is a safe and effective alternative to open suction-assisted brachioplasty (using the Pascal and Le Louarn technique) in patients with severe arm adiposity and moderate brachial ptosis (grade 2b arm ptosis as described by El Khatib classification). Proper patient selection remains critical for the success of this treatment strategy and requires precise clinical analysis as described.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

PMID:35259140 | DOI:10.1097/PRS.0000000000009058

IEEE Trans Neural Netw Learn Syst. 2022 Mar 8;PP. doi: 10.1109/TNNLS.2022.3151683. Online ahead of print.

ABSTRACT

Domain adaptation is concerned with the problem of generalizing a classification model to a target domain with little or no labeled data, by leveraging the abundant labeled data from a related source domain. The source and target domains possess different joint probability distributions, making it challenging for model generalization. In this article, we introduce domain neural adaptation (DNA): an approach that exploits nonlinear deep neural network to 1) match the source and target joint distributions in the network activation space and 2) learn the classifier in an end-to-end manner. Specifically, we employ the relative chi-square divergence to compare the two joint distributions, and show that the divergence can be estimated via seeking the maximal value of a quadratic functional over the reproducing kernel hilbert space. The analytic solution to this maximization problem enables us to explicitly express the divergence estimate as a function of the neural network mapping. We optimize the network parameters to minimize the estimated joint distribution divergence and the classification loss, yielding a classification model that generalizes well to the target domain. Empirical results on several visual datasets demonstrate that our solution is statistically better than its competitors.

PMID:35259116 | DOI:10.1109/TNNLS.2022.3151683

IEEE Trans Pattern Anal Mach Intell. 2022 Mar 8;PP. doi: 10.1109/TPAMI.2022.3157444. Online ahead of print.

ABSTRACT

The integral probability metric (IPM) equips generative adversarial nets (GANs) with the necessary theoretical support for comparing statistical moments in an embedded domain of the critic, while stabilising their training and mitigating the mode collapse issues. For enhanced intuition and physical insight, we introduce a generalisation of IPM-GANs which operates by directly comparing probability distributions rather than their moments. This is achieved through characteristic functions (CFs), a powerful tool that uniquely comprises all information about any general distribution. For rigour, we first theoretically prove the ability of the CF loss to compare probability distributions, and proceed to establish the physical meaning of the phase and amplitude of CFs. An optimal sampling strategy is then developed to calculate the CFs, and an equivalence between the embedded and data domains is proved under the reciprocal theory. This makes it possible to seamlessly combine IPM-GAN with an auto-encoder structure by an advanced anchor architecture, which adversarially learns a semantic low-dimensional manifold for both generation and reconstruction. This efficient reciprocal CF GAN (RCF-GAN) structure, uses only two modules and a simple training strategy to achieve the state-of-the-art bi-directional generation. Experiments demonstrate the superior performance of RCF-GAN on both regular (images) and irregular (graph) domains.

PMID:35259097 | DOI:10.1109/TPAMI.2022.3157444

IEEE Trans Haptics. 2022 Mar 8;PP. doi: 10.1109/TOH.2022.3156122. Online ahead of print.

ABSTRACT

Time order errors have been investigated in several fields, and the time delay between subsequent stimuli in discrimination tasks is one example of such errors. However, the effect of these types of errors in thermal discrimination tasks is understudied. To evaluate the effect of inter-stimulus interval (ISI) on thermal perception, we used a discrimination task with a staircase method between two non-zero thermal stimuli. We found that JND ISI=0s was 3.10 and increased by 11.9% and 21.2% at JND ISI=3s and JND ISI=9s, respectively. Statistical analysis revealed that ISI was a statistically significant effect (p < 0.05) on thermal perception in our task. Future studies on thermal perception should keep the ISI consistent and report the time.

PMID:35259114 | DOI:10.1109/TOH.2022.3156122

J Am Coll Health. 2022 Mar 8:1-9. doi: 10.1080/07448481.2022.2038178. Online ahead of print.

ABSTRACT

OBJECTIVE: The COVID-19 pandemic has drastically increased use of remote-delivered mental health services. This study identifies advantages and limitations of remote-delivered services on college campuses to inform mental health delivery post-pandemic. Methods: Clinicians (n = 30) were asked to evaluate COVID-19’s impact on their work, environment, and wellness in an online survey. Qualitative data was coded using a thematic analysis approach, while quantitative data was analyzed using descriptive statistics. Results: Many clinicians reported benefits of remote services, including increased accessibility, greater convenience, no change in therapeutic alliance, and decreased stress for clinicians. Clinicians also experienced challenges such as social isolation, technological difficulties, and personal/family concerns. Clinicians envisioned a hybrid service combining online and in-person activities post-pandemic. Conclusions: Overall, remote-delivered mental health services on college campuses have potential in increasing treatment quality while highlighting a necessity for further research in hybrid mental health delivery.

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07448481.2022.2038178 .

PMID:35259062 | DOI:10.1080/07448481.2022.2038178

J Am Coll Health. 2022 Mar 8:1-5. doi: 10.1080/07448481.2022.2039158. Online ahead of print.

ABSTRACT

Objective: Internet and development of digital media as a tool for online promotions provides avenues for early recruitment of college students into risky drinking. The objective of the study was to examine prevalence of alcohol promotions on web-based media and its possible effects on alcohol drinking by sex among college students in Kenya. Participants and Methods: A sample of 836 out of 1354 (61.7%) second and final year students in the school of education of a public urban university in Kenya participated in this online cross-sectional survey using awareness of online alcohol marketing and TWEAK questionnaires. Results: Facebook attracted most alcohol post per day (χ=3.6) and other apps collectively had least alcohol post per day (χ=0.8). Spearman’s correlation show significant association between online alcohol promotions and risky drinking (0.37; p < 0.001). At the overall level of exposure to online alcohol promotions on web-based media and risky drinking, we perceived a statistical significance difference (p < 0.001) in favor of male respondents. The regression model was successful in explaining approximately 56% of the adjusted variance in risky drinking habits. Conclusion: This significant level presence of online liquor promotions suggest that the youth had fairly open access to the mixed beverage creator’s items through web-based media stages which could impact youth to take part in early liquor drinking propensity. There was substantial presence of online alcohol promotions via web-based media scene that was related to risky drinking. Lastly, sex and online alcohol promotions could contribute to risky drinking among college students in Kenya.

PMID:35259070 | DOI:10.1080/07448481.2022.2039158

Strabismus. 2022 Mar 8:1-12. doi: 10.1080/09273972.2022.2046114. Online ahead of print.

ABSTRACT

This study aimed to calculate the dose-response relationship and predictors of visual acuity (VA) improvement following occlusion therapy at the IWK Health Center Eye Clinic and to add to amblyopia therapy dose-response relationship literature. A retrospective chart review was performed, considering patients who reached an occlusion therapy outcome at the IWK Eye Clinic between 2012 and 2019. The treatment outcome was defined as equal VA or stable VA for three consecutive clinical visits despite reported compliance. Subjective patching hours from parental reports, not prescribed hours, were used for statistical analyses. One hundred and thirty-four patients (66 females and 68 males) ages 2-11 years were included. Results showed a dose-response relationship of 224 hours/0.1logMAR increase in VA and total dose of 1344 hours for full-time occlusion and 504 hours for part-time occlusion was required to reach outcome VA. The fastest VA improvement occurred with younger age at treatment initiation, during the first 4 weeks of treatment, and in patients with strabismic and/or severe amblyopia. Classification of amblyopia, age, VA chart, initial distance VA (amblyopic eye), and treatment dose predicted the hour dose-response relationship. Dose-response relationship was faster in younger participants, in participants with strabismic and severe amblyopia, and during the first month of occlusion. Additionally, by creating a GLM model of dose-response relationship, relationship calculations can be performed. Therefore, an estimated timeline can be developed to allow allocation of clinical resources and to prepare patients for the treatment duration required and possibly increase treatment compliance.

PMID:35259060 | DOI:10.1080/09273972.2022.2046114