How Lazy Are Pet Cats Really? Using Machine Learning and Accelerometry to Get a Glimpse into the Behaviour of Privately Owned Cats in Different Households.

Surprisingly little is known about how the home environment influences the behaviour of pet cats. This study aimed to determine how factors in the home environment (e.g., with or without outdoor access, urban vs. rural, presence of a child) and the season influences the daily behaviour of cats. Using accelerometer data and a validated machine learning model, behaviours including being active, eating, grooming, littering, lying, scratching, sitting, and standing were quantified for 28 pet cats. Generalized estimating equation models were used to determine the effects of different environmental conditions. Increasing cat age was negatively correlated with time spent active (p < 0.05). Cats with outdoor access (n = 18) were less active in winter than in summer (p < 0.05), but no differences were observed between seasons for indoor-only (n = 10) cats. Cats living in rural areas (n = 7) spent more time eating than cats in urban areas (n = 21; p < 0.05). Cats living in single-cat households (n = 12) spent more time lying but less time sitting than cats living in multi-cat households (n = 16; p < 0.05). Cats in households with at least one child (n = 20) spent more time standing in winter (p < 0.05), and more time lying but less time sitting in summer compared to cats in households with no children (n = 8; p < 0.05). This study clearly shows that the home environment has a major impact on cat behaviour.

The Use of Triaxial Accelerometers and Machine Learning Algorithms for Behavioural Identification in Domestic Cats (Felis catus): A Validation Study.

Animal behaviour can be an indicator of health and welfare. Monitoring behaviour through visual observation is labour-intensive and there is a risk of missing infrequent behaviours. Twelve healthy domestic shorthair cats were fitted with triaxial accelerometers mounted on a collar and harness. Over seven days, accelerometer and video footage were collected simultaneously. Identifier variables (n = 32) were calculated from the accelerometer data and summarized into 1 s epochs. Twenty-four behaviours were annotated from the video recordings and aligned with the summarised accelerometer data. Models were created using random forest (RF) and supervised self-organizing map (SOM) machine learning techniques for each mounting location. Multiple modelling rounds were run to select and merge behaviours based on performance values. All models were then tested on a validation accelerometer dataset from the same twelve cats to identify behaviours. The frequency of behaviours was calculated and compared using Dirichlet regression. Despite the SOM models having higher Kappa (>95%) and overall accuracy (>95%) compared with the RF models (64-76% and 70-86%, respectively), the RF models predicted behaviours more consistently between mounting locations. These results indicate that triaxial accelerometers can identify cat specific behaviours.

Prolonged glucocorticoid administration affects oocyte morphology in cats (Felis catus) undergoing an ovarian stimulation protocol.

While captivity-related stress and the associated rise in baseline glucocorticoid (GC) concentrations have been linked to ovarian quiescence in some felid species, no study has examined the effects of elevated GC on oocyte quality. This study examined the effects of exogenous GC administration on the ovarian response and oocyte quality of domestic cats after an ovarian stimulation protocol. Entire mature female cats were divided into treatment (n = 6) and control (n = 6) groups. Cats in the GC treatment (GCT) group were given 1 mg kg-1 oral prednisolone daily from Day 0-45. All cats (n = 12) were given 0.088 mg kg-1 day-1 progesterone orally from Day 0-37, before treatment with 75 IU eCG im to induce follicular growth on Day 40, followed by 50 IU hCG im 80 h later to induce ovulation. Cats were ovariohysterectomised 30 h after the hCG treatment. Blood samples were collected on Days 0, 10, 30 and 40 (prior to eCG treatment), 80 h after eCG treatment, and on Day 45 for cortisol, glucose, prednisolone, oestradiol, and progesterone analysis. Cortisol concentrations did not differ between treatment groups throughout the study. Mean glucose concentrations were higher in the GCT cats (P = 0.004). Prednisolone was undetectable in all samples. Oestradiol and progesterone concentrations confirmed that the eCG treatment stimulated follicular activity and ovulation in all cats. Following ovariohysterectomy, the ovarian responses were graded (1 = excellent, 4 = poor) and oocytes retrieved from the oviducts. Each oocyte was given a total oocyte score (TOS: using an 9-point scale, 8 = best) based on four parameters: oocyte morphology, size, ooplasm uniformity and granularity, and zona pellucida (ZP) thickness and variation. Ovulation was confirmed in all cats, with a mean of 10.5 ± 1.1 ovulations per cat. Ovarian mass, ovarian response, number of ovulations, and oocyte recovery did not differ between groups. Oocyte diameter did not differ between the groups, but the ZP was thinner in the GCT group (3.1 ± 0.3 µm vs. 4.1 ± 0.3 µm, P = 0.03). The TOS was similar between treatment and control cats, but the ooplasm grade was lower (1.5 ± 0.1 vs. 1.9 ± 0.1, P = 0.01) and there was a tendency for ZP grade to be poorer (0.8 ± 0.1 vs. 1.2 ± 0.2; P = 0.08) in the treatment group. In conclusion, the GC treatment resulted in morphological changes to oocytes collected following ovarian stimulation. Whether these changes would affect fertility warrants further investigation.

Electrocution Risk of Capacitive Discharge Shocks: Application to Electric Vehicle Charging.

It is difficult to electrocute (induce ventricular fibrillation) with capacitive discharge shocks. With small capacitance values, the high voltages required for the necessary charge are rarely seen in industrial situations (e.g. electric vehicle charging stations). On the other hand, with large capacitance values, the discharge time is so great that the shock couples inefficiently with the cardiac cells. The update to IEC 60479-2 sets the C1 "mostly-safe" charge limit of 3 mC for a short "impulse function" pulse. We calculated the equivalent capacitor stored charge for an arbitrary capacitance value using the simple single membrane time constant model for the cardiac response. The peak membrane response was set equal to that of the 3 mC impulse function response to calculate the safe values for stored charge, voltage, and energy. The total stored charge, per se, cannot be used simplistically to estimate the danger of a capacitive discharge shock. A capacitive-discharge shock cannot be accurately compared to a rectangular shock with a duration equal to the shock time constant. The greater the capacitance, the larger the fraction of wasted charge in coupling to the heart and thus the shorter equivalent duration compared to the shock time constant. For a capacitive discharge shock this translates to a stored charge of 3 mC increasing up to 9 mC for a 10 capacitor using the assumed 575 load for an electric-vehicle (EV) charging station. In the area of interest for 1 - 10 the safe voltage ranges from 1300 to 4700 V, which includes the 1500-VDCscope of EV charger standard IEC 61851-23. For C > 100 the voltage asymptote is 700 V.

Exogenous glucocorticoid treatment affects Sertoli cell load and epididymal sperm quality in domestic cats (Felis catus).

Elevated glucocorticoid (GC) concentrations associated with captivity-related stress have been linked to impaired testicular function and low sperm quality in felids, but direct physiological evidence is lacking. This study assessed the effects of exogenous GC treatment on felid testicular function using the domestic cat (Felis catus) as a model species. Sixteen intact male cats aged 2.4 ± 0.8 years (mean ± SEM) were divided randomly into treatment (n = 8) and control (n = 8) groups. Treatment cats were given 1 mg kg-1 oral prednisolone daily for 50 days. Blood samples were taken on Days 0 (first prednisolone treatment), 2, 4, 7, 10, 20, 30, 40, 50 (prior to neutering) and 60 of the trial. All cats were orchiectomised on day 50, epididymal sperm assessed, and the testes fixed for histological assessment. Testosterone concentrations did not differ between the two groups. While sperm motility was similar between the treatment and control groups, cats given prednisolone had a higher proportion of morphologically abnormal sperm in both the caput (72.5% vs. 59.6%, P < 0.001) and cauda (56.7% vs. 35.8%, P < 0.001) epididymis. Testicular histomorphometric data and total number of germ cells per seminiferous tubule cross section did not differ between groups, nor did the relative abundance of spermatogonia, spermatocytes, and spermatids. Cats given prednisolone had fewer Sertoli cells per tubule cross-section than those in the control group (17.1 ± 0.9 vs. 19.7 ± 0.8, P = 0.04), which was likely related to higher rates of Sertoli cell apoptosis in treatment versus control cats (0.25 ± 0.02 vs. 0.10 ± 0.02 apoptotic Sertoli cells per tubule, respectively; P < 0.001). Sertoli cell load (number of germ cells per Sertoli cell) was also higher in the treatment group than in the control group (11.5 ± 0.8 vs. 9.4 ± 1.2 germ cells per Sertoli cell, respectively; P < 0.001), and was positively correlated with the percentage of morphologically abnormal sperm in the epididymis (r2 = 0.78, P < 0.001). Prednisolone treatment resulted in an increase in the proportion of abnormal sperm in the epididymis, which may be explained by an increased nurturing demand on a reduced Sertoli cell population. These findings provide novel evidence to support the hypothesis that elevated GC concentrations, such as those resulting from captivity-related stress, have the potential to impair testicular function and sperm quality in felids.

Electrical injury: Chronic pain, somatosensory dysfunction, post traumatic stress and movement disorders.

INTRODUCTION AND AIMS: We aimed in this case series to identify shortcomings in assessment of long-term painful and psychosocial consequences of EI and to demonstrate the value of biopsychosocial assessment and the commonalities in outcomes. METHODS: We retrospectively analyzed 15 cases from 2004 to 2019 of adult claimants assessed in a medico-legal practice for complex chronic pain disorders secondary to EI. Extensive biopsychosocial information, including 165 data items on pre- and post-injury observations, were collected on each. Cutaneous and deep pressure somatosensory examination was performed and questionnaires for psychological evaluation and restless legs syndrome completed. A comprehensive literature review and descriptive analysis was conducted. RESULTS: Pre-injury, most claimants worked (12/15), did not receive government benefits (14/15) and had no primary pain disorder (9/15). EIs were severe (14/15), where chronic post-traumatic pain, typically high impact with nociplastic features, was regional in 5 and widespread in 10. Somatosensory signs in wide distribution in all cases implied central sensitization. Movement disorders included digital dyskinesia (5/15), involuntary muscle contractions (7/15) and restless legs syndrome in 7. Diagnostic and Statistical Manual of Mental Disorders (DSM-5) post-traumatic stress disorder (PTSD) criteria were met in 12/15, and 14/15 experienced depression and impaired sleep. Severe social impacts, notably including loss of employment resulting in financial stresses, were common. CONCLUSIONS: Biological, psychological and social consequences of EI revealed extensive similarities. Disability was generally severe, moreso than indicated in clinical records, influenced by relative paucity of primary pathology, inadequate pain-orientated somatosensory testing and insufficient application of biopsychosocial assessment and management.

Accelerometry and infrared thermography show potential for assessing ovarian activity in domestic cats (Felis catus).

Accurate and reliable monitoring of ovarian activity is challenging in many felids as current methods are either invasive or not amenable to real-time assessments. This 45-day study assessed whether accelerometry and infrared (IR) thermography can be used to address these limitations. Intact female domestic cats (n = 12) were given 0.088 mg kg-1 day-1 altrenogest (progestin) orally for 37 days to suppress follicular growth. On Day 40, cats were given 75 IU eCG im to induce follicular growth and 50 IU hCG im 80 h later to induce ovulation. Cats were ovariohysterectomised 30-31 h after the hCG treatment. Actical® accelerometers were fitted to the cats' collars and activity monitored continuously from the start of the altrenogest treatment until ovariohysterectomy. Infrared images of the perivulvar, perianal, and gluteal area were taken of each cat on Day 30 and daily from Days 36-45 of the study. Perivulvar temperature (PVT), PVT relative to gluteal temperatures (PVT-GT), and PVT relative to perianal temperature (PVT-PAT) were recorded for each image. Blood samples were collected on Days 0, 10, 30, and 40, immediately prior to the hCG treatment, and at the time of ovariohysterectomy. Serum oestradiol and progesterone concentrations indicated complete ovarian suppression by Day 30 and, together with morphological assessment of the ovaries, confirmed the induction of follicular growth and ovulation in all cats. Daily activity counts differed among cats (P < 0.001), so the daily activity counts of each cat were converted to a proportional change from the average daily activity count from Days 30-39 (defined as the 'proportional daily activity'). Proportional daily activity counts increased after the stimulation of follicular growth with eCG, with peak levels (2.03 ± 0.29-fold higher than pre-treatment levels; P = 0.006) occurring three days after the eCG treatment. The PVT-GT showed the greatest sensitivity to detect subtle changes in body temperature, increasing from early to late follicular growth (1.96 ± 0.33 °C increase from Day 41-43; P < 0.001) and decreasing after hCG-induced ovulation (1.24 ± 0.41 °C decrease from Day 43-45; P = 0.01). In conclusion, both accelerometry and IR thermography show potential as non-invasive, real-time methods for assessing ovarian activity in cats, but further research is required to determine if these methods could be used to monitor natural/non-stimulated oestrous cycles.

Ventricular Fibrillation Threshold vs Alternating Current Shock Duration.

INTRODUCTION: International basic safety limits for utility-frequency electrical currents have long been set by the International Electrotechnical Commission 60479-1 standard. These were inspired by a linear-section plot proposed by Biegelmeier in 1980 with current given as a function of the shock duration. This famous plot has contributed to safe electrical circuit design internationally and has properly earned significant amount of respect over its 35 years of life. However, some possible areas for improvement have been suggested. METHODS: We searched for all animal studies of ventricular fibrillation threshold versus duration that used a forelimb to hindlimb connection that had at least 3 durations tested. We found 6 such studies and they were then used to calculate a new C3 curve after normalizing the data. RESULTS: A rational function model fit the animal data with r2 = .96. Such a correlation calculation tends to underweight the smaller values, so we also correlated the log threshold values and this had a correlation of r2=.94. CONCLUSION: Existing ventricular fibrillation threshold current versus duration data can be fitted with a simple rational function. This can provide a useful update to IEC 60479-1.

Humidity and Ventricular Fibrillation: When Wet Welding can be Fatal.

INTRODUCTION: Arc welding is generally considered very safe electrically. There have been electrocution cases with welders in high humidity environments. When dry, the flux coatings tend to have sufficient electrical resistance to limit the current below that required for the induction of VF (ventricular fibrillation). METHODS: We tested 4 welding electrodes for resistance in both dry and wet conditions. To estimate the cardiac current density - in a worst-case scenario - we used a 20k element finite-element bioimpedance model with 1 cm of skin and fat along with 1 cm of muscle before the heart of 5 cm dimensions. Between the heart and a metal plate we assumed 5 cm of lung and 1 cm of skin and fat. RESULTS: Welding electrode flux is highly resistive when dry. However, when saturated with moisture the resistance is almost negligible as far as dangerous currents in a human. The FEM model calculated a current density of > 7 mA/cm2 on the ventricular epicardium with a source of 80 V at the welding rod. CONCLUSION: In conditions of high humidity, a supine operator, in contact with a coated welding electrode to the precordial region of the body can be fibrillated with the AC open-circuit voltage. Most reported DC fatalities were probably due to pseudo-DC outputs that were merely rectified AC without smoothing.

Computational models for contact current dosimetry at frequencies below 1 MHz.

Electric contact currents (CC) can cause muscle contractions, burns, or ventricular fibrillation which may result in life-threatening situations. In vivo studies with CC are rare due to potentially hazardous effects for participants. Cadaver studies are limited to the range of tissue's electrical properties and the utilized probes' size, relative position, and sensitivity. Thus, the general safety standards for protection against CC depend on a limited scientific basis. The aim of this study was therefore to develop an extendable and adaptable validated numerical body model for computational CC dosimetry for frequencies between DC and 1 MHz. Applying the developed model for calculations of the IEC heart current factors (HCF) revealed that in the case of transversal CCs, HCFs are frequency dependent, while for longitudinal CCs, the HCFs seem to be unaffected by frequency. HCFs for current paths from chest or back to hand appear to be underestimated by the International Electrotechnical Commission (IEC 60479-1). Unlike the HCFs provided in IEC 60479-1 for longitudinal current paths, our work predicts the HCFs equal 1.0, possibly due to a previously unappreciated current flow through the blood vessels. However, our results must be investigated by further research in order to make a definitive statement. Contact currents of frequencies from DC up to 100 kHz were conducted through the numerical body model Duke by seven contact electrodes on longitudinal and transversal paths. The resulting induced electric field and current enable the evaluation of the body impedance and the heart current factors for each frequency and current path.

Monitoring ovarian function and detecting pregnancy in felids: A review.

Reliable detection and monitoring of estrus and pregnancy is essential to the effective ex situ conservation of endangered felids. Here, we review the current methods used to detect estrus and pregnancy in felids and describe the advantages and limitations of each. A total of 194 felid-focused publications were reviewed. The methods used included behavioral assessments (61 publications across 24 species), hormone monitoring (124 studies across 28 species), fecal protein monitoring (two studies in cheetah), ultrasonography (31 publications across seven species), vaginal cytology (22 publications across nine species), and laparoscopy (70 publications across 19 species). Behavior-based assessments of reproductive state are often inconsistent and unreliable in felids; thus hormone measurement is the most frequently used method for monitoring estrous cycles (66% of studies). In non-domestic felids, non-invasive fecal- or urine-based hormone metabolite analyses are preferred to blood assessments (66% of endocrine-based publications). While the measurement of fecal estrogen and progestin metabolites are useful for the retrospective assessment of ovarian activity, their use for real-time detection of estrus is limited. Vaginal cytology, laparoscopy and ultrasonography provide an acute and immediate determination of reproductive state but usually require anesthesia or sedation, which can prevent ovulation and cause abortions; thus, their use for pregnancy diagnosis is limited. Fecal progesterone or prostaglandin F2α metabolites can be used to detect pregnancy in most felids (the exception being fecal progestins for Lynx spp.), but only during mid-to-late gestation. Urinary relaxin measurement is a promising method for earlier pregnancy diagnosis (30-40% duration of gestation) but is presently limited by poor assay sensitivity due to the lack of a feline-specific relaxin antibody. Elevated levels of fecal immunoglobulin J chain have been investigated as a tool to detect pregnancy in cheetah (>80% accuracy), but research is lacking on other species. We conclude that there is no single 'best method' for monitoring ovarian activity and detecting pregnancy in felids, and current best practice would involve a combination of existing methods. Non-invasive methods for detecting estrus and pregnancy in felids (e.g., accelerometry and infrared thermography) should also be considered to augment existing methods.

Protocols for documentation of electrical injuries for electrical safety inspectors and emergency medical practitioners.

BACKGROUND: Electric shocks are common, and victims report difficulty in finding practitioners with knowledge of the injury. Medical Practitioners, especially in private practice, report lack of knowledge of the injury and lack of expertise in assessing and treating the injury. The authors are often requested to suggest investigation protocols, assessment protocols, and treatment protocols, and to provide educational information. METHODS: The international body establishing electrical standards on the effects of current on the body (International Electrotechnical Commission, Maintenance Team 4 (MT4) of Technical Committee 64 (TC64)) have established protocols for the factors which require documentation and reporting of the injury. This article provides a narrative approach to using these protocols in accord with the standards (IEC 60479). The level of evidence is Level III (US/Canada classification). TYPE: This article collects together and collates physical and medical aspects of investigating electric shocks, and summarizes those of importance, and which are potentially forgotten. The thoroughness of initial assessment is emphasized. SUBSTANCE: Summaries are set out to guide first attenders and emergency medical personnel as to findings and observations which must be recorded for later comprehensive medicolegal reporting and which are often overlooked. CONCLUSION: Wider teaching in the nature of electric shocks will enhance assessment of victims and thorough recording of pertinent information and thus will enhance later medicolegal reporting. Many such factors are initially overlooked and lead to inadequate reporting for forensic purposes.

High Impedance Electrical Accidents: Importance of Source and Subject Impedance.

In most cases, the diagnosis of an electrical injury or electrocution is straightforward. However, there is a necessity for much closer analysis in many cases. There exist sophisticated electrical safety standards that predict outcomes for shocks of various currents applied to different parts of the body. Unfortunately, the actual current is almost never known in an accident investigation. A common source of errors is the assumption that the source (including the return) has zero impedance. Another surprisingly common problem is the erroneous assumption that the body current is equal to the source current capability. METHODS: We used the following methodology for analyzing such cases: (1) Determine body pathway, (2) Estimate body pathway impedance, (3) Determine source voltage, (4) Determine source impedance, (5) Calculate delivered current using total pathway impedance, and (6) Ignore available current as it is largely confounding in most cases. RESULTS: We analyzed 6 difficult cases using the above methodology. This includes 2 subtle situations involving pairs of matched case-control subjects where a subject was electrocuted while his work partner was not. CONCLUSIONS: Careful calculations of the amplitude and duration of the shock is required for understanding the limits and potential causation of such electrical injury. This requires the determination of both the source and body pathway impedance. Available current is usually irrelevant and overemphasized.

Dosimetry for Ventricular Fibrillation Risk with Short Electrical Pulses: History and Future.

Electrical safety limits for unidirectional pulses with short durations are increasingly important due to the proliferation of electric-car and factory energy storage systems with potentially dangerous voltages. Electrocution by a short-duration direct-current pulse is not understood as well as that by alternating current and the data are limited. The primary international guidance comes from IEC 60479-2 section 11. METHODS: We have analyzed the dosimetry for short pulse safety limits based on a fuller understanding of the scientific principles involved and human data. Implantable defibrillators have been tested by externally delivering short-duration pulses giving us human data which we analyze for this paper. RESULTS: The present IEC current limit (60479-2:11) for short pulse durations is based on an exponent of -0.68 in the equation I = d-0.68, (d being pulse width), while the correct exponent should be -1.0 given the constant charge for the VF threshold of short pulses. We also propose a baseline charge value based on the human data. CONCLUSIONS: Charge-based VF thresholds give the correct dosimetry for short-duration pulses. Results from this paper should be considered in support of revising the IEC 60479-2 standard section 11.

Post electrical or lightning injury syndrome: a proposal for an American Psychiatric Association's Diagnostic and Statistical Manual formulation with implications for treatment.

In the past, victims of electrical and lightning injuries have been assessed in a manner lacking a systematic formulation, and against ad hoc criteria, particularly in the area of neuropsychological disability. In this manner patients have, for example, only been partially treated, been poorly or incorrectly diagnosed, and have been denied the full benefit of compensation for their injuries. This paper contains a proposal for diagnostic criteria particularly for the neuropsychological aspects of the post injury syndrome. It pays attention to widely published consistent descriptions of the syndrome, and a new cluster analysis of post electrical injury patients. It formulates a proposal which could be incorporated into future editions of the American Psychiatric Association's Diagnostic and Statistical Manual (DSM). The major neuropsychological consequences include neurocognitive dysfunction, and memory subgroup dysfunction, with ongoing consequences, and sometimes including progressive or delayed psychiatric, cognitive, and/or neurological symptoms. The proposed diagnostic criteria insist on a demonstrated context for the injury, both specifying the shock circumstance, and also physical consequences. It allows for a certain delay in onset of symptoms. It recognizes exclusory conditions. The outcome is a proposal for a DSM classification for the post electrical or lightning injury syndrome. This proposal is considered important for grounding patient treatment, and for further treatment trials. Options for treatment in electrical or lightning injury are summarised, and future trials are foreshadowed.

Neurological and neuropsychological consequences of electrical and lightning shock: review and theories of causation.

Injuries from lightning and electrical injuries involve multiple systems of the body, however neurological symptoms are very widely reported. A disabling neuropsychological syndrome is also noted. This paper presents a comprehensive review of neurological and neuropsychological symptoms. Partial theories of causation for these injuries have been advanced, however, there is no convincing explanation for both delay in onset of symptoms and also the genesis of the neuropsychological syndrome. A theory of causation is proposed which satisfies both these constraints. This theory suggests circulating hormones such as cortisol, together with nitric oxide and oxidant free radicals from glutamatergic hyper-stimulation, act on tissues remote from the injury path including the hippocampus. This theory opens a research path to explore treatment options.

Further documentation of remote effects of electrical injuries, with comments on the place of neuropsychological testing and functional scanning.

It is not always recognized that morbidity from electrical injury is not confined to effects in the pathway of current flow. Indeed a major element of the disability suffered by victims occur from effects remote to the line of current passage. Recent papers have rightly drawn further attention to this, and it is an active area of controversy and research. This paper documents the authors experience in this area and confirms the recognizable elements of remote injuries which are seen to be generally psychological in nature. The question of mechanisms of causation of these disabilities is raised. This paper then presents summary results of a collation of neuropsychological investigations and functional cerebral scanning in an attempt to correlate the two. It is concluded that it is possible to overlook the remote effects of electrical injury to the detriment of victims.