Negative symptoms and cognitive impairment are associated with distinct motivational deficits in treatment resistant schizophrenia.

BACKGROUND: Motivational deficits are a central feature of the negative syndrome in schizophrenia. They have consistently been associated with reduced willingness to expend physical effort in return for monetary rewards on effort based decision making (EBDM) paradigms. Nevertheless, the mechanisms underlying such altered performance are not well characterised, and it remains unclear if they are driven purely by negative symptoms, or also in part by cognitive impairment, antipsychotic treatment or even positive symptoms. Here we investigated the impact of all these factors using a paradigm that has not previously been used to measure EBDM in schizophrenia. METHODS: Forty treatment resistant schizophrenia (TRS) patients on clozapine and matched controls (N = 80) completed a well validated EBDM task which offers monetary rewards in return for physical effort. Choice and reaction time data was analysed using logistic regressions, as well as Bayesian hierarchical drift diffusion modelling (HDDM). Behavioural parameters were compared between groups and their association with negative symptoms, cognitive function and serum clozapine levels were assessed. RESULTS: Overall, TRS patients accepted significantly less offers than controls during effort-based decision making, suggesting they were less motivated. They demonstrated reduced sensitivity to increasing rewards, but surprisingly were also less averse to increasing effort. Despite a positive correlation between negative symptoms and cognitive function in TRS, reward sensitivity was associated only with cognitive performance. In contrast, reduced effort aversion correlated with negative symptom severity. Clozapine levels and positive symptoms were not associated with either behavioural parameter. CONCLUSION: Motivational deficits in TRS are characterised by both diminished reward sensitivity and reduced effort aversion during EBDM. Cognitive dysfunction and negative symptom severity account for distinct aspects of these behavioural changes, despite positive associations between themselves. Overall, these findings demonstrate that negative symptoms and cognitive impairment have significant independent contributions to EBDM in TRS, thereby opening the possibility of individualised treatment targeting these mechanisms to improve motivation.

Evaluation of different genomic regions of rotavirus B and rotavirus C for development of real-time RT‒PCR assays.

BACKGROUND: The causative agents of diarrhea, rotavirus B (RVB) and rotavirus C (RVC) are common in adults and patients of all age groups, respectively. Due to the Rotavirus A (RVA) vaccination program, a significant decrease in the number of gastroenteritis cases has been observed globally. The replacement of RVA infections with RVB, RVC, or other related serogroups is suspected due to the possibility of reducing natural selective constraints due to RVA infections. The data available on RVB and RVC incidence are scant due to the lack of cheap and rapid commercial diagnostic assays and the focus on RVA infections. The present study aimed to develop real-time RT‒PCR assays using the data from all genomic RNA segments of human RVB and RVC strains available in the Gene Bank. RESULTS: Among the 11 gene segments, NSP3 and NSP5 of RVB and the VP6 gene of RVC were found to be suitable for real-time RT‒PCR (qRT‒PCR) assays. Fecal specimens collected from diarrheal patients were tested simultaneously for the presence of RVB (n = 192) and RVC (n = 188) using the respective conventional RT‒PCR and newly developed qRT‒PCR assays. All RVB- and RVC-positive specimens were reactive in their respective qRT‒PCR assays and had Ct values ranging between 23.69 and 41.97 and 11.49 and 36.05, respectively. All known positive and negative specimens for other viral agents were nonreactive, and comparative analysis showed 100% concordance with conventional RT‒PCR assays. CONCLUSIONS: The suitability of the NSP5 gene of RVB and the VP6 gene of RVC was verified via qRT‒PCR assays, which showed 100% sensitivity and specificity. The rapid qRT‒PCR assays developed will be useful diagnostic tools, especially during diarrheal outbreaks for testing non-RVA rotaviral agents and reducing the unnecessary use of antibiotics.

Persistence of effort in apathy.

The syndrome of apathy has generated increasing interest in recent years as systematic evaluations have revealed its high prevalence and strong negative impact on quality of life across a wide range of neurological and psychiatric conditions. However, although several theoretical models have been proposed to account for various aspects of the condition, understanding of this syndrome is still incomplete. One influential model has proposed that apathy might be described as a quantitative reduction of goal-directed behaviour in comparison to an individual's prior level of functioning. Persistence of activity defined as the capacity to continue with a task - sometimes in the face of setbacks, high levels of difficulty or fatigue - is a crucial but understudied aspect of goal-directed behaviour. Surprisingly, it has not been investigated yet in the context of apathy. Here, we provide an overview of theoretical and experimental aspects of persistence in effort that might assist to develop methods for the investigation of persistence in human behaviour, particularly within the pathologic context of apathy.

Rotavirus C infections in asymptomatic piglets in India, 2009-2013: genotyping and phylogenetic analysis of all genomic segments.

Asymptomatic infection with rotavirus C (RVC) was observed in pigs in India, with a detection rate of 20%. Sequencing of the VP6, VP7, and NSP4 genes of RVC strains identified the genotypes I7/I10, G1, and E5, respectively. Full genome sequencing of one of these strains revealed that the genotypes of the VP4, VP1, VP2, VP3, NSP1, NSP2, NSP3, and NSP5 genes were P1, R1, C1, M3, A1, N5, T5, and H1, respectively. The detection of porcine RVC strains at two different locations in India at different time points strongly suggests that they are circulating continuously in the pig population through asymptomatic infections.

Prevalence and genetic diversity of gastroenteritis viruses in hospitalized children < 5 years of age in Maharashtra state, Western India, 2017-2019.

Four gastroenteritis viruses were responsible for 54% of the acute gastroenteritis (AGE) cases in children hospitalized between May 2017 and December 2019 in Pune city of Maharashtra state, Western India. The majority (79%) of the children were <2 years of age. The prevalence of Rotavirus A (RVA) was 30.5% followed by 14.3% for norovirus, 8.4% for adenovirus, and 5.5% for astrovirus. The severity of the disease was highest in patients with coinfections compared with the patients with a single infection or negative for all (p = 0.024). Genotyping analysis showed that the majority of the RVA-positive samples (66%) could be typed as G3P[8], 63.6% of the norovirus as GII.4 Sydney [P16], 44% of the adenovirus as type 41%, and 56.2% of the astrovirus as astrovirus type 1. The almost equivalent prevalence of rotavirus and nonrotaviruses and acute gastroenteritis (AGE) cases without known etiology in around 46% of the cases was noted in the present study. Our data highlight that after the recent inclusion of rotavirus vaccines as a part of the National Immunization schedule in India, conducting extensive AGE surveillance in children should include nonrotaviruses such as norovirus.

Effect of curcumin on growth, biofilm formation and virulence factor gene expression of Porphyromonas gingivalis.

Porphyromonas gingivalis is a keystone pathogen and major colonizer in host tissue which plays a pivotal role in periodontitis among the other polymicrobial infections. Increasing facts demonstrate that curcumin has antibacterial activity and anti-biofilm effect against the periodontopathogens through diverse mechanisms that have a positive impact on periodontal health. The present study was aimed to elucidate the effect of curcumin on biofilm formation and virulence factor gene expression of P. gingivalis. By using gene expression studies, we exploited the mechanism of anti-biofilm effects of curcumin on P. gingivalis. The minimum inhibitory concentration and minimum bactericidal concentration of curcumin for both ATCC and clinical strains of P. gingivalis were found to be 62.5 and 125 µg ml-1 respectively. Curcumin prevented bacterial adhesion and biofilm formation in a dose-dependent manner. Further, curcumin attenuated the virulence of P. gingivalis by reducing the expression of genes coding for major virulence factors, including adhesions (fimA, hagA, and hagB) and proteinases (rgpA, rgpB, and kgp). The results indicated that curcumin has shown anti-biofilm as well as antibacterial activity against P. gingivalis. Further, curcumin because of its pleiotropic actions could be a simple and inexpensive therapeutic strategy in the treatment of periodontal disease.

Third-trimester in utero fetal brain diffusion tensor imaging fiber tractography: a prospective longitudinal characterization of normal white matter tract development.

BACKGROUND: White matter is responsible for inter-neuronal connections throughout the brain that are a driving force in cognitive development. Diffusion tensor imaging (DTI) fiber tractography has been used to evaluate white matter development in the fetal brain; however, longitudinal studies of DTI fiber tractography to assess white matter development in the third trimester are lacking. OBJECTIVE: To characterize in utero longitudinal changes in the fetal brain DTI fiber tracts of normal third-trimester fetuses. MATERIALS AND METHODS: For this single-center prospective longitudinal observational pilot study, we recruited 28 pregnant females with normal third-trimester pregnancies who had routine prenatal ultrasound. MRI of the in utero fetal brain was performed with a Siemens 1.5-tesla (T) Espree scanner at 31 weeks, 33 weeks and 36 weeks of gestation, with 14 DTI tractography parameters quantified in 7 brain regions using DTI-studio version 2.4 (Johns Hopkins University, Baltimore, MD; n=98 measurements). We used multilevel mixed models to examine the relationship between longitudinal changes in DTI measurements and between 98 DTI measurements at 31 weeks and 4 routine fetal brain anatomical biometrics (n=392 assessments). RESULTS: We observed statistically significant decreases in radial diffusivity and apparent diffusion coefficient in 13 of 14 brain regions from 31 weeks to 36 weeks of gestation (P<0.001 for all regions except the genu of the corpus callosum). Significant decreases in radial diffusivity from weeks 33 to 36 and weeks 31 to 36 were seen in the corticospinal tracts, centrum semiovale, posterior limb of the internal capsule, and crus cerebri (P<0.001 for all). When considering all possible combinations of DTI fiber tract measurements and the routine morphological fetal brain biometrics, only 6% (24/392) had a significant association (P<0.05), indicating relative independence of the DTI fiber tract measurements from anatomical biometrics. CONCLUSION: In utero longitudinal changes in fetal brain DTI fiber tractography are quantifiable in normal third-trimester fetuses and are largely independent of morphological brain changes.

Investigation of a large waterborne acute gastroenteritis outbreak caused by group B rotavirus in Maharashtra state, India.

An acute gastroenteritis outbreak at Devli Karad village, Maharashtra, India with an attack rate of 22.6% affected mainly adolescent and adult population. The viral investigations conducted on fecal specimens of patients hospitalized indicated the presence of rotavirus B (RVB) using RNA polyacrylamide gel electrophoresis and reverse transcription polymerase chain reaction. The samples collected from the source of drinking water also showed the presence of the only RVB. Absence of other viral agents and identification of RVB of genotype G2 as the etiological agent of the acute gastroenteritis outbreak highlights, the necessity of monitoring RVB, the viral agent known for its large outbreak potential.

Multidetector CT Findings in the Abdomen and Pelvis after Damage Control Surgery for Acute Traumatic Injuries.

After experiencing blunt or penetrating trauma, patients in unstable condition who are more likely to die of uncorrected shock than of incomplete injury repairs undergo emergency limited exploratory laparotomy, which is also known as damage control surgery (DCS). This surgery is part of a series of resuscitation steps, with the goal of stabilizing the patient's condition, with rapid surgical control of hemorrhage followed by supportive measures in the intensive care unit before definitive repair of injuries. These patients often are imaged with multidetector CT within 24-48 hours of the initial surgery. Knowledge of this treatment plan is critical to CT interpretation, because there are anatomic derangements and foreign bodies that would not be present in patients undergoing surgery for other reasons. Patients may have injuries beyond the surgical field that are only identified at imaging, which can alter the care plan. Abnormalities related to the resuscitation period such as the CT hypoperfusion complex and ongoing hemorrhage can be recognized at CT. Familiarity with these imaging and clinical findings is important, because they can be seen not only in trauma patients after DCS but also in other patients in the critical care setting. The interpretation of imaging studies can be helped by an understanding of the diagnostic challenges of grading organ injuries with surgical materials in place and the awareness of potential artifacts on images in these patients. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by LeBedis .

An immortalized microglial cell line (Mocha) derived from rat cochlea.

Microglia are glial-immune cells that are essential for the function and survival of the central nervous system. Microglia not only protect neural tissues from immunological insults, but also play a critical role in neural development and repair. However, little is known about the biology of microglia in the cochlea, the auditory portion of the inner ear. In this study, we detected TMEM119+, CD11b+, CD45+ and Iba1+ populations of cells in the rat cochlea, particularly in Rosenthal's canal, inner sulcus and stria vascularis. Next, we isolated and enriched the population of CD11b+ cells from the cochlea and immortalized these cells with the 12S E1A gene of adenovirus in a replication-incompetent retroviral vector to derive a novel microglial cell line, designated Mocha (microglia of the cochlea). The resulting Mocha cells express a number of markers consistent with microglia and respond to lipopolysaccharide (LPS) stimulation by upregulation of genes (Cox2, ICAM-1, Il6r, Ccl2, Il13Ra and Il15Ra) as well as releasing cytokines (IL-1beta, IL-12, IL-13 and RANTES). As evidence of microglial function, Mocha cells phagocytose fluorescent beads at 37°C, but not at 4°C. The expression pattern of microglial markers in Mocha cells suggests that immortalization leads to a more primitive phenotype, a common phenomenon in immortalized cell lines. In summary, Mocha cells display key characteristics of microglia and are now available as a useful model system for the study of cochlear microglial behavior, both in vitro and in vivo.

Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans: Relationship of serotypes to herpesvirus and periodontal status in Indian subjects.

BACKGROUND: The virulence of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in any individual depends on the type of strain of this bacterium. To our knowledge, there have been no studies reported in Indian subjects about A. actinomycetemcomitans serotype occurrence, co-existence with herpes virus and the possible influence of such co-existence on periodontal pathology. METHODS: Subjects for this study were a subset of a larger study to identify the prevalence of A. actinomycetemcomitans in chronic periodontitis. A total of 63 subjects (12 periodontally healthy and 51 with chronic periodontitis) who were positive for A. actinomycetemcomitans were serotyped for strain-level identification. The presence of Human Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) was tested in subgingival plaque samples by polymerase chain reaction. RESULTS: All five serotypes a to e were detected. Of the samples analyzed 38.09% harbored a single serotype, 36.5% had two serotypes, 6.3% demonstrated three and 4.7% demonstrated four serotypes. None of the samples showed presence of JP2 strain. Serotypes b, c, and e were most frequently identified in these individuals (46.03%, 36.5% and 38.09% respectively). Presence of serotypes b and c and absence of serotype d was associated with increased PD and CAL. Among 63 samples analyzed, 11 samples had CMV, four samples had EBV and nine samples had both these viruses. The PD and CAL were significantly higher (p = 0.04) when a combination of CMV and one of the serotypes was present indicating a pathological role of the coexistence. CONCLUSION: Multiple serotypes are associated with chronic periodontitis in Indians, however, JP2 strains are not detectable in this cohort. Presence of multiple serotypes and a combination of any serotype with herpesvirus is associated with greater severity of the disease.

Mind the gap: temporal discrimination and dystonia.

BACKGROUND AND PURPOSE: One of the most widely studied perceptual measures of sensory dysfunction in dystonia is the temporal discrimination threshold (TDT) (the shortest interval at which subjects can perceive that there are two stimuli rather than one). However the elevated thresholds described may be due to a number of potential mechanisms as current paradigms test not only temporal discrimination but also extraneous sensory and decision-making parameters. In this study two paradigms designed to better quantify temporal processing are presented and a decision-making model is used to assess the influence of decision strategy. METHODS: 22 patients with cervical dystonia and 22 age-matched controls completed two tasks (i) temporal resolution (a randomized, automated version of existing TDT paradigms) and (ii) interval discrimination (rating the length of two consecutive intervals). RESULTS: In the temporal resolution task patients had delayed (P = 0.021) and more variable (P = 0.013) response times but equivalent discrimination thresholds. Modelling these effects suggested this was due to an increased perceptual decision boundary in dystonia with patients requiring greater evidence before committing to decisions (P = 0.020). Patient performance on the interval discrimination task was normal. CONCLUSIONS: Our work suggests that previously observed abnormalities in TDT may not be due to a selective sensory deficit of temporal processing as decision-making itself is abnormal in cervical dystonia.

Anti-Leukemic Activity of Shikonin: Role of ERP57 in Shikonin Induced Apoptosis in Acute Myeloid Leukemia.

BACKGROUND/AIMS: ER-Stress and activation of unfolded protein response belong to the major factors involved in chemoresistance in cancer cells. In this study we investigated the effect of shikonin on the survival of acute myeloid leukemia cells and the role of ER-stress protein ERP57, a protein disulfide isomerase, in improvement of chemotherapy. METHODS: Using MTT assay we studied cytotoxic effects of shikonin on HL-60 cells. The flow cytometry was adopted to examine the shikonin induced mode of cell death in HL-60 cells. The overall protein expression alteration resulting from shikonin treatment was investigated using proteomics methods. Western blotting was performed to quantify the alteration in protein expression in HL-60 after shikonin treatment. Silencing and overexpression studies were carried out to highlight the therapeutic role of ERP57 in shikonin effect on AML cells. RESULTS: Shikonin induces apoptosis in HL-60 cells without significant effect on Primary cells from healthy volunteers. The apoptotic effect was dose and time dependent and was accompanied by strong alteration in cell proteome. Among the proteins targeted by shikonin, ERP57 was significantly downregulated in HL-60 after treatment. Compared to healthy control ERP57 was found to be highly expressed in AML cell line HL60 and was downregulated after shikonin treatment. Overexpression of ERP57 protected HL-60 from shikonin induced apoptosis, whereas knockdown of ERP57 expression resulted in increase in shikonin induced apoptosis. CONCLUSIONS: Our results demonstrate that ERP57 plays a crucial role in resistance towards shikonin induced apoptosis in AML cells. Targeting of ERP57 might offer a new therapeutic option for the treatment of acute myeloid leukemia.

A Method for Delineation of Bone Surfaces in Photoacoustic Computed Tomography of the Finger.

Photoacoustic (PA) imaging of interphalangeal peripheral joints is of interest in the context of using the synovial membrane as a surrogate marker of rheumatoid arthritis. Previous work has shown that ultrasound (US) produced by absorption of light at the epidermis reflects on the bone surfaces within the finger. When the reflected signals are backprojected in the region of interest, artifacts are produced, confounding interpretation of the images. In this work, we present an approach where the PA signals known to originate from the epidermis are treated as virtual US transmitters, and a separate reconstruction is performed as in US reflection imaging. This allows us to identify the bone surfaces. Furthermore, the identification of the joint space is important as this provides a landmark to localize a region-of-interest in seeking the inflamed synovial membrane. The ability to delineate bone surfaces allows us to identify not only the artifacts but also the interphalangeal joint space without recourse to new US hardware or a new measurement. We test the approach on phantoms and on a healthy human finger.

Diversity of Drimia indica (Roxb.) Jessop and its relationship to Drimia nagarjunae using phenotypic traits and molecular markers.

In the present study, we explored the diversity of different accessions of Drimia indica and its relation to D. nagarjunae using phenotypic traits and molecular markers. Twenty populations of D. indica, from different parts of India, were compared with D. nagarjunae, an endangered medicinal plant collected from Andhra Pradesh, India. Two species showed appreciable phenotypic diversity in number of leaves, leaf indices, bulb circumference, bulb length and length of roots. The principal component analysis (PCA) performed on above 5 quantitative characters to determine relationship among populations, has distinguished D. nagarjunae from D. indica phenotypically. Genetic diversity was analysed using RAPD and ISSR primers which produced reproducible bands in 8 RAPD and 3 ISSR primers. A total of 89 amplicons were observed, of which 69 (77.53%) were polymorphic. Cluster diagram and phylogenetic linkage showed that D. nagarjunae formed a separate cluster, showing no similarity with any of the populations of D. indica. The molecular marker data correlated with PCA of phenotypic traits. Current investigations have demonstrated that the statistical approach for phenotypic characters and molecular markers analysis can be applied to study diversity in Drimia species.

Evaluation of loop-mediated isothermal amplification method for efficient detection of the periodontopathic bacteria Porphyromonas gingivalis.

Background: Periodontitis is a multifactorial, polymicrobial oral inflammatory illness brought on by oral pathogens. Porphyromonas gingivalis is a Gram-negative, obligatory anaerobic, black-pigmented coccobacillus and is regarded as a primary etiological factor in the progression of periodontitis. Rapid, highly senstitive and specific detection methods are emerging. The present study aimed to evaluate the loop-mediated isothermal amplification (LAMP) technique for efficiently detecting P. gingivalis from subgingival plaque samples of chronic periodontitis patients. Materials and Methods: This study included 50 subgingival plaque samples from patients suffering from chronic periodontitis. The DNA (Deoxyribonucleic acid) was extracted by the "modified proteinase K" method. A set of six primers, targeting the pepO gene of P. gingivalis, was used for conducting LAMP. The amplification was visualized by naked-eye detection and agarose electrophoresis. Conventional polymerase chain reaction (PCR) and real-time qantitative PCR (qPCR) were carried out by targeting the 16SrRNA (16S ribosomal ribonucleic acid) gene of P. gingivalis. Results: The results showed that LAMP detected P. gingivalis in 40 out of 50 samples (80%). Whereas, qPCR and conventional PCR technique detected P. gingivalis in 38 (76%) and 33 (66%) samples respectively. The sensitivity and specificity of the LAMP method were 94.87% and 90.90%, respectively. With qPCR, the sensitivity and specificity were found to be 92.30% and 81.81%, respectively, whereas, with conventional PCR, it was found to be 76.92% and 72.72%, respectively. Conclusion: LAMP is an efficient technique for quick, accurate, and reliable identification of P. gingivalis from subgingival plaque samples. The technique needs to be validated analytically, and further studies can be conducted by taking saliva and/or gingival crevicular fluid samples from periodontitis patients.

Genome sequencing and functional analysis of a multipurpose medicinal herb Tinospora cordifolia (Giloy).

Tinospora cordifolia (Willd.) Hook.f. & Thomson, also known as Giloy, is among the most important medicinal plants that have numerous therapeutic applications in human health due to the production of a diverse array of secondary metabolites. To gain genomic insights into the medicinal properties of T. cordifolia, the genome sequencing was carried out using 10× Genomics linked read and Nanopore long-read technologies. The draft genome assembly of T. cordifolia was comprised of 1.01 Gbp, which is the genome sequenced from the plant family Menispermaceae. We also performed the genome size estimation for T. cordifolia, which was found to be 1.13 Gbp. The deep sequencing of transcriptome from the leaf tissue was also performed. The genome and transcriptome assemblies were used to construct the gene set, resulting in 17,245 coding gene sequences. Further, the phylogenetic position of T. cordifolia was also positioned as basal eudicot by constructing a genome-wide phylogenetic tree using multiple species. Further, a comprehensive comparative evolutionary analysis of gene families contraction/expansion and multiple signatures of adaptive evolution was performed. The genes involved in benzyl iso-quinoline alkaloid, terpenoid, lignin and flavonoid biosynthesis pathways were found with signatures of adaptive evolution. These evolutionary adaptations in genes provide genomic insights into the presence of diverse medicinal properties of this plant. The genes involved in the common symbiosis signalling pathway associated with endosymbiosis (Arbuscular Mycorrhiza) were found to be adaptively evolved. The genes involved in adventitious root formation, peroxisome biogenesis, biosynthesis of phytohormones, and tolerance against abiotic and biotic stresses were also found to be adaptively evolved in T. cordifolia.

Past rewards capture spatial attention and action choices.

The desire to increase rewards and minimize punishing events is a powerful driver in behaviour. Here, we assess how the value of a location affects subsequent deployment of goal-directed attention as well as involuntary capture of attention on a trial-to-trial basis. By tracking eye position, we investigated whether the ability of an irrelevant, salient visual stimulus to capture gaze (stimulus-driven attention) is modulated by that location's previous value. We found that distractors draw attention to them significantly more if they appear at a location previously associated with a reward, even when gazing towards them now leads to punishments. Within the same experiment, it was possible to demonstrate that a location associated with a reward can also bias subsequent goal-directed attention (indexed by action choices) towards it. Moreover, individuals who were vulnerable to being distracted by previous reward history, as indexed by oculomotor capture, were also more likely to direct their actions to those locations when they had a free choice. Even when the number of initial responses was made to be rewarded and punished stimuli were equalized, the effects of previous reward history on both distractibility and action choices remained. Finally, a covert attention task requiring button-press responses rather than overt gaze shifts demonstrated the same pattern of findings. Thus, past rewards can act to modulate both subsequent stimulus-driven as well as goal-directed attention. These findings reveal that there can be surprising short-term costs of using reward cues to regulate behaviour. They show that current valence information, if maintained inappropriately, can have negative subsequent effects, with attention and action choices being vulnerable to capture and bias, mechanisms that are of potential importance in understanding distractibility and abnormal action choices.

Obstetric consultant weekend on-call shift patterns have no effect on the management of spontaneous labour in a large maternity hospital.

Recent reports observe poorer healthcare outcomes during the weekend. Many attribute this weekend effect to a reduced consultant presence. This study evaluates differences in labour management on weekends vs weekdays. A total of 20,187 deliveries, all resulting from spontaneous labour, in the same large U.K. maternity hospital were examined. Labour management was analysed both for the department as a whole, and separately for each consultant, for differences in weekend and weekday practice. Results showed no statistically significant results of a difference in any of the measures analysed. On a weekend, deliveries were no more likely to be vaginal, p = 0.485, assisted, p = 0.771 or by caesarean section, p = 0.526. There was also no difference between individual consultants. It was concluded that for spontaneous labour, there is no difference in patient management on weekends vs weekdays, either in the department as a whole, or between individual consultants in our study.

Photoacoustic spectrum analysis for spherical target size and optical property determination: A feasibility study.

The photoacoustic signal generated by an optically absorbing target is determined by the spatial profile of absorbed optical energy within the target. The analysis of the time profile and frequency content of the signal enables the recovery of the geometry of the object, as well as information about the optical properties. The photoacoustic response of spheres with a homogeneous absorbed optical energy profile is well described, and it is known that the width of the photoacoustic pulse is determined by the diameter of the sphere and its sound speed. In practice, the optical attenuation coefficients within the sphere will result in an inwardly decaying fluence profile leading to a similarly decaying absorbed optical energy profile. Further, the optical attenuation coefficients may be inhomogeneously distributed in the sphere. The implication for both cases is that the existing model for spheres does not fully apply. In this work, we developed analytical expressions for the photoacoustic time traces and amplitude spectra generated by a sphere with absorbed optical energy only in a spherical shell, and by a sphere with an inwardly decaying optical energy profile. Numerical simulations and experiments were conducted on these two imperfect sphere types. Fitting our model to the simulated or measured spectra allowed us to test our model's ability to extract the sphere size and optical properties. We found that the radii can be recovered with high accuracy, even when the frequency response of the detector recording the photoacoustic pulse is not precisely known. The model was found to be less sensitive in recovering the optical attenuation coefficient, but it is feasible when the detector's frequency response is well known.