Spatial relation categorization in infants and deep neural networks.

Spatial relations, such as above, below, between, and containment, are important mediators in children's understanding of the world (Piaget, 1954). The development of these relational categories in infancy has been extensively studied (Quinn, 2003) yet little is known about their computational underpinnings. Using developmental tests, we examine the extent to which deep neural networks, pretrained on a standard vision benchmark or egocentric video captured from one baby's perspective, form categorical representations for visual stimuli depicting relations. Notably, the networks did not receive any explicit training on relations. We then analyze whether these networks recover similar patterns to ones identified in development, such as reproducing the relative difficulty of categorizing different spatial relations and different stimulus abstractions. We find that the networks we evaluate tend to recover many of the patterns observed with the simpler relations of "above versus below" or "between versus outside", but struggle to match developmental findings related to "containment". We identify factors in the choice of model architecture, pretraining data, and experimental design that contribute to the extent the networks match developmental patterns, and highlight experimental predictions made by our modeling results. Our results open the door to modeling infants' earliest categorization abilities with modern machine learning tools and demonstrate the utility and productivity of this approach.

Grounded language acquisition through the eyes and ears of a single child.

Starting around 6 to 9 months of age, children begin acquiring their first words, linking spoken words to their visual counterparts. How much of this knowledge is learnable from sensory input with relatively generic learning mechanisms, and how much requires stronger inductive biases? Using longitudinal head-mounted camera recordings from one child aged 6 to 25 months, we trained a relatively generic neural network on 61 hours of correlated visual-linguistic data streams, learning feature-based representations and cross-modal associations. Our model acquires many word-referent mappings present in the child's everyday experience, enables zero-shot generalization to new visual referents, and aligns its visual and linguistic conceptual systems. These results show how critical aspects of grounded word meaning are learnable through joint representation and associative learning from one child's input.

Neoadjuvant calcium electroporation for potentially curable colorectal cancer.

BACKGROUND: The development of new perioperative treatment modalities to activate the immune system in colorectal cancer might have a beneficial effect on reducing the risk of recurrence after surgery. Calcium electroporation is a promising treatment modality that potentially modulates the tumor microenvironment. The aim of this study was to evaluate the safety of the procedure in the neoadjuvant setting in localized left-sided colorectal cancer (CRC). METHODS: The study included patients with potentially curable sigmoid or rectal cancer with no indication for other neoadjuvant treatment. Patients were offered calcium electroporation as a neoadjuvant treatment before elective surgery. Follow-up visits were conducted on the preoperative day before elective surgery, POD2, POD14, and POD30, with an evaluation of adverse events, impact on elective surgery, clinical examination, and quality of recovery. RESULTS: Endoscopic calcium electroporation was performed as an outpatient procedure in all 21 cases, with no procedure-related complications reported. At follow-up, five adverse events were registered, two of which were classified as serious adverse events. Surgery was performed as planned in 19 patients (median time to surgery, 8 days), and the final two patients underwent surgery with a delay due to adverse events (14 and 33 days). No significant impact on the quality of recovery scores nor inflammatory markers were seen before and after calcium electroporation, nor baseline and POD30. CONCLUSIONS: Endoscopic calcium electroporation is a safe and feasible procedure in patients with potentially curable CRC. The study showed limited side effects and limited impact on the following elective surgical resection.

Long term sexual outcomes of Mayer Rokitansky Küster Hauser Syndrome patients after Uncu-modified Davydov procedure.

Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome has an incidence of 1 in 4000. The absence of the vagina and uterus results in sexual dysfunction and infertility. The first-line treatment is vaginal dilatation. There exists a number of second-line surgical options including the Uncu-modified Davydov procedure. Objective: To determine the complication rate, anatomical outcomes, and long-term sexual outcomes of MRKH syndrome patients after Uncu-modified Davydov procedure. Materials and Methods: Patients with MRKH syndrome who underwent paramesonephric remnant-supported laparoscopic double-layer peritoneal pull-down vaginoplasty (aka Uncu-modified Davydov procedure) between January 2008 and December 2021. The procedure involves laparoscopic circular dissection of the pelvic peritoneum followed by pulling down, through the opened vaginal orifice, and suturing the vaginal cuff with the support of uterine remnants. The long-term complication rate, anatomical outcomes, and sexual function outcomes (as measured by Female Sexual Function Index (FSFI)) were ascertained. Main outcome measures: Main Outcome Measures: The long-term complication rate, anatomical outcomes and FSFI survey results. Results: A total of 50 patients with MRKH syndrome underwent the Uncu-modified Davydov procedure between Jan 2008- Dec 2021. There were four perioperative complications: three bladder injuries (6%) and one rectal serosa injury (2%). Four long-term postoperative complications were identified: one vesicovaginal fistula (2%), one recto-vaginal fistula (2%), and two vaginal stenoses (4%). All patients were physically examined at least one year after surgery. The mean vaginal length was 8.4 + 1.9 cm. The mean FSFI score was 31.5 + 3.9 (minimum score of 24, maximum score of 36). Conclusion: Conclusion: The Uncu-modified Davydov procedure has been demonstrated to be a safe and effective treatment option with high female sexual function index scores for patients with MRKH syndrome. What is new?: The long-term complication rate, anatomical and sexual outcomes of Uncu-modified laparoscopic peritoneal pull-down vaginoplasty were reported in this study. The results indicated that the surgical approach could be used in selective MRKH patients who failed first-line self-dilatation therapy.

Effects of Preheating and Sonic Delivery Techniques on the Internal Adaptation of Bulk-fill Resin Composites.

OBJECTIVE: To compare the effects of conventional (hand-placed), sonic, or preheated insertion techniques on the internal adaptation of bulk-fill resin composites. METHODS AND MATERIALS: A total of 150 freshly extracted human third molars were used to prepare standardized cylindrical occlusal cavities. Teeth were divided into five main groups according to the resin composites: 1 incremental (Clearfil Majesty Posterior [CMP]) and four paste-like bulk-fill (SonicFill 2 [SF2], VisCalor bulk [VCB], Filtek One bulk-fill restorative [FBR], and Tetric EvoCeram bulk-fill [TEB]). Each main group was divided into three subgroups according to the placement technique: conventional, preheating, and sonic delivery (n=10). In the conventional placement technique, cavities were filled manually. In the sonic insertion technique, a specific handpiece (SonicFill Handpiece; Kerr Corporation) was used. In the preheating technique, a heating device (Caps Warmer, Voco, Cuxhaven, Germany) was used to warm the resin composites before placement. Internal voids (%) of the completed restorations were calculated with microcomputed tomography. Data was analyzed with two-way analysis of variacne followed by Tukey's multiple comparisons test (α=0.05). RESULTS: All resin composites showed fewer internal gaps with preheating compared with the conventional placement (p<0.05). For all resin composites other than SF2, preheating provided fewer internal gaps than that of the sonic placement (p<0.05). Sonic placement led to fewer internal gaps compared with the conventional placement, but only for SF2 and FBR (p<0.05). For the conventional placement, the lowest gap percentage was observed with the incremental resin composite (CMP, p<0.05). Among all groups, the lowest gap percentages were observed for preheated VCB followed by sonically inserted SF2 (p<0.05). CONCLUSION: The best internal adaptation was observed in sonically inserted SF2 and preheated VCB, which were the manufacturers' recommended insertion techniques. Preheating considerably improved the internal adaptation of all resin composites, except for that of SF2.

Prediction of 90-day mortality after surgery for colorectal cancer using standardized nationwide quality-assurance data.

BACKGROUND: Personalized risk assessment provides opportunities for tailoring treatment, optimizing healthcare resources and improving outcome. The aim of this study was to develop a 90-day mortality-risk prediction model for identification of high- and low-risk patients undergoing surgery for colorectal cancer. METHODS: This was a nationwide cohort study using records from the Danish Colorectal Cancer Group database that included all patients undergoing surgery for colorectal cancer between 1 January 2004 and 31 December 2015. A least absolute shrinkage and selection operator logistic regression prediction model was developed using 121 pre- and intraoperative variables and internally validated in a hold-out test data set. The accuracy of the model was assessed in terms of discrimination and calibration. RESULTS: In total, 49 607 patients were registered in the database. After exclusion of 16 680 individuals, 32 927 patients were included in the analysis. Overall, 1754 (5.3 per cent) deaths were recorded. Targeting high-risk individuals, the model identified 5.5 per cent of all patients facing a risk of 90-day mortality exceeding 35 per cent, corresponding to a 6.7 times greater risk than the average population. Targeting low-risk individuals, the model identified 20.9 per cent of patients facing a risk less than 0.3 per cent, corresponding to a 17.7 times lower risk compared with the average population. The model exhibited discriminatory power with an area under the receiver operating characteristics curve of 85.3 per cent (95 per cent c.i. 83.6 to 87.0) and excellent calibration with a Brier score of 0.04 and 32 per cent average precision. CONCLUSION: Pre- and intraoperative data, as captured in national health registries, can be used to predict 90-day mortality accurately after colorectal cancer surgery.

Intermammary pilonidal sinus in women. Diagnosis and treatment.

BACKGROUND: Globally, the term pilonidal sinus disease (PSD) is most frequently used for lesions in the sacrococcygeal region. The inter-mammary sulcus is a rare location for pilonidal sinus abscesses. Our study examined the causes of inter-mammary PSD (IMPSD), which is rarely seen in the literature and our treatment approach. MATERIAL: We retrospectively analyzed patients referred to our hospital's general surgery clinic between 2012 and 2018. Twelve patients were operated on for IMPSD during these six years. An excision, including all sinus openings, was planned, and a D-shaped incision was performed. Sinus openings and tracts underlying the skin were excised in toto. Subcutaneous flaps were created to shift the incision from the midline plane to reduce the recurrence rate. The minimum duration for the follow-up was 24 months. Eight patients were suffering from polycystic ovary syndrome. Progesterone and testosterone levels of the patients were normal. Prior studies evaluating PSD and hormone levels of female patients showed no correlation. CONCLUSIONS: IMPSD is a disease that should be kept in mind if induration and abscess in the inter-mammary region are present. The risk of recurrence is high if no proper excision is planned. A D-shaped incision including all sinus tract openings and a midline shift prevented our series' possible recurrences. HIPPOKRATIA 2020, 24(2): 84-87.

Publisher Correction: A diverse range of factors affect the nature of neural representations underlying short-term memory.

The original and corrected figures are shown in the accompanying Publisher Correction.

A diverse range of factors affect the nature of neural representations underlying short-term memory.

Sequential and persistent activity models are two prominent models of short-term memory in neural circuits. In persistent activity models, memories are represented in persistent or nearly persistent activity patterns across a population of neurons, whereas in sequential models, memories are represented dynamically by a sequential activity pattern across the population. Experimental evidence for both models has been reported previously. However, it has been unclear under what conditions these two qualitatively different types of solutions emerge in neural circuits. Here, we address this question by training recurrent neural networks on several short-term memory tasks under a wide range of circuit and task manipulations. We show that both sequential and nearly persistent solutions are part of a spectrum that emerges naturally in trained networks under different conditions. Our results help to clarify some seemingly contradictory experimental results on the existence of sequential versus persistent activity-based short-term memory mechanisms in the brain.

Distribution and community composition of lichens on mature mangroves (Avicennia marina subsp. australasica (Walp.) J.Everett) in New Zealand.

Mangrove forests of a single trees species, Avicennia marina subsp. australasica are widespread in the upper North Island of New Zealand, but there is little available information on the diversity of epiphytes such as lichens within them. A survey of 200 trees from 20 mangrove sites recorded a total of 106 lichen species from 45 genera. Two of these species are considered to be 'Threatened', five 'At Risk' and 27 'Data Deficient'. Multiple regression indicated that tree diameter (DBH) and mean annual rain days positively influenced site species richness. Multidimensional scaling showed that sites from the same geographical region generally formed distinct clusters. Redundancy analysis indicated that mean annual wet days, latitude and DBH measurably influenced species composition.

Efficient probabilistic inference in generic neural networks trained with non-probabilistic feedback.

Animals perform near-optimal probabilistic inference in a wide range of psychophysical tasks. Probabilistic inference requires trial-to-trial representation of the uncertainties associated with task variables and subsequent use of this representation. Previous work has implemented such computations using neural networks with hand-crafted and task-dependent operations. We show that generic neural networks trained with a simple error-based learning rule perform near-optimal probabilistic inference in nine common psychophysical tasks. In a probabilistic categorization task, error-based learning in a generic network simultaneously explains a monkey's learning curve and the evolution of qualitative aspects of its choice behavior. In all tasks, the number of neurons required for a given level of performance grows sublinearly with the input population size, a substantial improvement on previous implementations of probabilistic inference. The trained networks develop a novel sparsity-based probabilistic population code. Our results suggest that probabilistic inference emerges naturally in generic neural networks trained with error-based learning rules.Behavioural tasks often require probability distributions to be inferred about task specific variables. Here, the authors demonstrate that generic neural networks can be trained using a simple error-based learning rule to perform such probabilistic computations efficiently without any need for task specific operations.

Association of apelin, endoglin and endocan with diabetic peripheral neuropathy in type 2 diabetic patients.

OBJECTIVE: Diabetic peripheral neuropathy is a common complication of type-2 diabetes mellitus. Endocan, apelin and endoglin are thought to be associated with endothelial dysfunction, angiogenesis and inflammation. In this study, we planned to evaluate these markers in diabetic peripheral neuropathy patients. PATIENTS AND METHODS: This single-blind, controlled clinical study was conducted on 99 type 2 diabetic patients with or without diabetic peripheral neuropathy and 53 healthy volunteer controls. Physical and laboratory examinations were done in all groups. In these groups, Endoglin, apelin and endocan levels were measured with ELISA method. RESULTS: Endoglin, apelin and endocan concentrations in diabetic peripheral neuropathy patients were higher than other diabetes mellitus patients and healthy controls. Similarly, diabetes mellitus patient's endoglin, apelin and endocan levels were higher than healthy controls. The differences were statistically significant. We detected a significant positive correlation between endoglin, apelin and endocan levels in all groups. CONCLUSIONS: Endoglin, apelin and endocan may reflect angiogenesis and endothelial dysfunction in diabetic peripheral neuropathy and they may be used as a marker in the future.

Analysis of pulp chamber of primary maxillary second molars using 3D micro-CT system: an in vitro study.

AIM: The aim of this study was to determine the positional relationship between the crown contour and the pulp chamber as well as the morphological characteristics of the pulp chamber using micro-CT in order to plan, in restorations of deciduous maxillary second molars, reconstructions with a volumetric rendering programme. STUDY DESIGN: In total 16 deciduous maxillary second molar teeth (8 from boys, 8 from girls) were used. The positional relationship between crown contour and pulp chamber was three-dimensionally observed by micro-CT. Differences in sex, dentin thickness and pulp volumes were evaluated using chi-square and paired t-tests. Differences were considered significant when P < 0.05. RESULTS: Dentin thickness was found to be 2.8 mm ± 0.2, mesiobuccally 3.15 mm ± 0.2 distobuccally 3.8 ± 0.3, which was statistically significant (p ≤ 0.05). The pulp volume for boys was 77 mm³ ± 4, for girls 64 mm³ ± 5, with a statistical significance (p ≤ 0.05). CONCLUSIONS: General differences could play a role when planning a treatment for a child; however for both genders it should be noted that mesiobuccal pulp horn is most likely to get exposed during cavity preparation.

Neural population coding of multiple stimuli.

In natural scenes, objects generally appear together with other objects. Yet, theoretical studies of neural population coding typically focus on the encoding of single objects in isolation. Experimental studies suggest that neural responses to multiple objects are well described by linear or nonlinear combinations of the responses to constituent objects, a phenomenon we call stimulus mixing. Here, we present a theoretical analysis of the consequences of common forms of stimulus mixing observed in cortical responses. We show that some of these mixing rules can severely compromise the brain's ability to decode the individual objects. This cost is usually greater than the cost incurred by even large reductions in the gain or large increases in neural variability, explaining why the benefits of attention can be understood primarily in terms of a stimulus selection, or demixing, mechanism rather than purely as a gain increase or noise reduction mechanism. The cost of stimulus mixing becomes even higher when the number of encoded objects increases, suggesting a novel mechanism that might contribute to set size effects observed in myriad psychophysical tasks. We further show that a specific form of neural correlation and heterogeneity in stimulus mixing among the neurons can partially alleviate the harmful effects of stimulus mixing. Finally, we derive simple conditions that must be satisfied for unharmful mixing of stimuli.

Toward ecologically realistic theories in visual short-term memory research.

Recent evidence from neuroimaging and psychophysics suggests common neural and representational substrates for visual perception and visual short-term memory (VSTM).Visual perception is adapted to a rich set of statistical regularities present in the natural visual environment. Common neural and representational substrates for visual perception and VSTM suggest that VSTM is adapted to these same statistical regularities too. This article discusses how the study of VSTM can be extended to stimuli that are ecologically more realistic than those commonly used in standard VSTM experiments and what the implications of such an extension could be for our current view of VSTM. We advocate for the development of unified models of visual perception and VSTM­probabilistic and hierarchical in nature­ incorporating prior knowledge of natural scene statistics.

Determining treatibility of primary teeth with pulpal exposure.

OBJECTIVES: To determine rates of pulpal exposure during caries removal with an excavator or a bur, to assess success rates of vital pulp therapies in both cases, to analyze pulpal bleeding as an indicator of primary teeth treatability. STUDY DESIGN: Of the 352 primary mandibular molars with deep carious lesions, 141 with pulp exposed during the removal of caries were grouped according to type of instrument causing pulpal exposure and existence of bleeding at the exposure site. Teeth suitable for direct pulp capping or formocresol pulpotomy were treated and followed up for two years. RESULTS: The difference between the rates of pulpal exposure with an excavator (52.5%) or a bur (47.5%) was insignificant. The treatment success rate of teeth with pulp exposed by an excavator (15.8%) was significantly lower than teeth with pulp exposed by a bur (48.8%), regardless of whether bleeding existed at the exposure site or not; however when bleeding existed, this difference was insignificant (15.8% and 40.6%, respectively). CONCLUSIONS: Pulpal exposure possibility during caries removal caused by an excavator and a bur was similar the treatment success rate was lower when the exposure was caused by an excavator the existence of pulpal bleeding resulted in mistakes in diagnoses.

A probabilistic clustering theory of the organization of visual short-term memory.

Experimental evidence suggests that the content of a memory for even a simple display encoded in visual short-term memory (VSTM) can be very complex. VSTM uses organizational processes that make the representation of an item dependent on the feature values of all displayed items as well as on these items' representations. Here, we develop a probabilistic clustering theory (PCT) for modeling the organization of VSTM for simple displays. PCT states that VSTM represents a set of items in terms of a probability distribution over all possible clusterings or partitions of those items. Because PCT considers multiple possible partitions, it can represent an item at multiple granularities or scales simultaneously. Moreover, using standard probabilistic inference, it automatically determines the appropriate partitions for the particular set of items at hand and the probabilities or weights that should be allocated to each partition. A consequence of these properties is that PCT accounts for experimental data that have previously motivated hierarchical models of VSTM, thereby providing an appealing alternative to hierarchical models with prespecified, fixed structures. We explore both an exact implementation of PCT based on Dirichlet process mixture models and approximate implementations based on Bayesian finite mixture models. We show that a previously proposed 2-level hierarchical model can be seen as a special case of PCT with a single cluster. We show how a wide range of previously reported results on the organization of VSTM can be understood in terms of PCT. In particular, we find that, consistent with empirical evidence, PCT predicts biases in estimates of the feature values of individual items and also predicts a novel form of dependence between estimates of the feature values of different items. We qualitatively confirm this last prediction in 3 novel experiments designed to directly measure biases and dependencies in subjects' estimates.

A fatal case of Behcet's disease.

We report the case of a 32-year-old man with new diagnosed Behcet's disease (BD) with cardiac, central nervous system and vascular involvement. Transthoracic echocardiography disclosed a thrombus in the right ventricle and another thrombus in the inferior vena cava (IVC). The color Doppler imaging was compatible with Budd-Chiari syndrome. Magnetic resonance imaging (MRI) of the brain revealed atrophy of brain stem and right hemisphere and a milimmetric lacunar infarct. Although therapy with urokinase, pulse methylprednisolone and cyclophosphamide was administered immediately, the patient died due to hepatic failure. BD should always be considered in the differential diagnosis of thromboses in the young and thrombotic events should be evaluated during the clinical course of BD.

Visual learning with reliable and unreliable features.

Existing studies of sensory integration demonstrate how the reliabilities of perceptual cues or features influence perceptual decisions. However, these studies tell us little about the influence of feature reliability on visual learning. In this article, we study the implications of feature reliability for perceptual learning in the context of binary classification tasks. We find that finite sets of training data (i.e., the stimuli and corresponding class labels used on training trials) contain different information about a learner's parameters associated with reliable versus unreliable features. In particular, the statistical information provided by a finite number of training trials strongly constrains the set of possible parameter values associated with unreliable features, but only weakly constrains the parameter values associated with reliable features. Analyses of human subjects' performances reveal that subjects were sensitive to this statistical information. Additional analyses examine why subjects were sub-optimal visual learners.

Investigation of pneumatized articular eminence in orthodontic malocclusions.

OBJECTIVES: To investigate the prevalence and characteristics of pneumatized articular tubercule (PAT) or eminence in an orthodontic patient population and to examine the possible correlations between different orthodontic malocclusions and pneumatized articular eminence types. SETTING AND SAMPLE POPULATION: Department of Orthodontics, Faculty of Dentistry, Ankara University, Turkey. MATERIAL AND METHODS: Pre-treatment panoramic radiographs were evaluated retrospectively from files of 1405 children and adolescents (459 boys and 946 girls) having various types of malocclusions. Diagnosis of PAT on the radiographs was recorded only if unequivocal pneumatization of the articular eminence could be seen or if the defect was located in the articular eminence posterior to the zygomaticotemporal suture, as a well-defined unilocular- or multilocular radiolucency. PAT was classified as unilocular or multilocular and unilateral or bilateral. Chi-square test was performed to evaluate age, gender, localization, type of malocclusion and prevalence differences. RESULTS: Sixty-six pneumatized articular eminences were found in 48 patients, representing a prevalence of 3.42%. The results of chi-square test showed no statistically significant differences considering age (p = 0.516), gender (p = 0.719), type of malocclusion (p = 0.155) and localization (p = 0.738). CONCLUSIONS: A relatively high rate of pneumatized articular eminence was observed among patients with orthodontic malocclusions (3.42%) when compared to the general population studies. Knowledge about these structures is helpful for the interpretation of cephalometric and panoramic radiographs and provides valuable information especially prior to temporomandibular joint surgery to avoid intra-operative reconstruction and complications.