SBS suppression using PRBS phase modulation with different orders.

The Brillouin instability (BI) caused by stimulated Brillouin scattering (SBS) can limit the output power of high-energy laser amplifiers. Pseudo-random bitstream (PRBS) phase modulation is an effective modulation technique to suppress BI. In this paper, we study the impact of the PRBS order and modulation frequency on the BI threshold for different Brillouin linewidths. PRBS phase modulation with a higher order will break the power into a larger number of frequency tones with a lower maximum power in each tone, leading to a higher BI threshold and a smaller tone spacing. However, the BI threshold may saturate when the tone spacing in the power spectra approaches the Brillouin linewidth. For a given Brillouin linewidth, our results allow us to determine the order of PRBS beyond which there is no further improvement in the threshold. When a specific threshold power is desired, the minimum PRBS order required decreases as the Brillouin linewidth increases. When the PRBS order is too large, the BI threshold deteriorates, and this deterioration occurs at smaller PRBS orders as the Brillouin linewidth increases. We investigate the dependence of the optimal PRBS order on the averaging time and fiber length, and we did not find a significant dependence. We also derive a simple equation that relates the BI threshold for different PRBS orders. Hence, the increase in BI threshold using an arbitrary order PRBS phase modulation may be predicted using the BI threshold from a lower PRBS order, which is computationally less time-consuming to compute.

Sex differences in acute health service contact after release from prison in Australia: a data linkage study.

OBJECTIVES: Women released from prison typically experience worse health outcomes than their male counterparts. We examined sex differences in the patterns, characteristics, and predictors of acute health service contact (AHSC) (i.e. ambulance and/or emergency department use) after release from prison. STUDY DESIGN: Data linkage study. METHODS: Baseline survey data from 1307 adults (21% women) within six weeks of expected release from prisons in Queensland, Australia (2008-2010) were linked prospectively with state-wide ambulance and emergency department, correctional, mental health, and death records. Crude and adjusted incidence rates and incidence rate ratios of AHSC were calculated overall and by sex. An Andersen-Gill model was fit to examine whether sex predicted AHSC. The interaction effect between sex and each model covariate was tested. RESULTS: The crude incidence rates of AHSC after release from prison were 1.4 (95% confidence interval [CI]: 1.3-1.5) and 1·1 (95%CI: 1.1-1.2) per person-year for women and men, respectively. The relationship between perceived physical health-related functioning at the baseline and AHSC was modified by sex (P = 0·039). The relationship between perceived health-related functioning and AHSC also differed among women. Compared to women who perceived their physical health as fair or good at the baseline, women who perceived their physical health as poor were at greater risk of AHSC (hazard ratio = 2.4, 95%CI: 1.4-3·9, P = 0.001) after release from prison. CONCLUSIONS: Among people released from prison, women's and men's AHSC differs depending on how they perceive their own physical health. The specific needs of women and men must be considered in transitional support policy and planning to improve their health outcomes.

Tradeoff between the Brillouin and transverse mode instabilities in Yb-doped fiber amplifiers.

The Brillouin instability (BI) due to stimulated Brillouin scattering (SBS) and the transverse (thermal) mode instability (TMI) due to stimulated thermal Rayleigh scattering (STRS) limit the achievable power in high-power lasers and amplifiers. The pump power threshold for BI increases as the core diameter increases, but the threshold for TMI may decrease as the core diameter increases. In this paper, we use a multi-time-scale approach to simultaneously model BI and TMI, which gives us the ability to find the fiber diameter with the highest power threshold. We formulate the equations to compare the thresholds of the combined and individual TMI and BI models. At the pump power threshold and below, there is a negligible difference between the full and individual models, as BI and TMI are not strong enough to interact with each other. The highest pump threshold occurs at the optimal core size of 43 µm for the simple double-clad geometry that we considered. We found that both effects contribute equally to the threshold, and the full BI and TMI model yields a similar threshold as the BI or TMI model alone. However, once the reflectivity is sufficiently large, we find in the full BI and TMI model that BI may trigger TMI and reduce the TMI threshold to a value lower than is predicted in simulations with TMI alone. This result cannot be predicted by models that consider BI and TMI separately. Our approach can be extended to more complex geometries and used for their optimization.

Accurate and efficient modeling of the transverse mode instability in high energy laser amplifiers.

We study the transverse mode instability (TMI) in the limit where a single higher-order mode (HOM) is present. We demonstrate that when the beat length between the fundamental mode and the HOM is small compared to the length scales on which the pump amplitude and the optical mode amplitudes vary, TMI is a three-wave mixing process in which the two optical modes beat with the phase-matched component of the index of refraction that is induced by the thermal grating. This limit is the usual limit in applications, and in this limit TMI is identified as a stimulated thermal Rayleigh scattering (STRS) process. We demonstrate that a phase-matched model that is based on the three-wave mixing equations can have a large computational advantage over current coupled mode methods that must use longitudinal step sizes that are small compared to the beat length.

Severity of cognitive disability and mental health court determinations about fitness to stand trial.

BACKGROUND: Little is known about the socio-demographic, clinical and legal determinants of mental health court decisions of unsoundness of mind and unfitness to stand trial for people with cognitive disability. We aimed to estimate the association between severity of cognitive disability and mental health court determinations of unsoundness or unfitness and describe the socio-demographic, clinical and legal factors that predict these determinations. METHODS: Case file data were extracted on 92 individuals who had a criminal case referred to the Queensland Mental Health Court between 1 January 2013 and 31 December 2014 due to cognitive disability. We fit a modified multivariable Poisson regression model to estimate the association between severity of cognitive impairment and mental health court determination, controlling for socio-demographic, clinical and legal factors. RESULTS: Adjusting for covariate effects, severity of cognitive impairment was positively associated with being found unfit to stand trial (adjusted prevalence risk ratio = 1.57; 95% confidence interval: 1.07, 2.33; P = 0.023), and comorbid psychotic disorder predicted an increased risk of being found unsound of mind at the time of offence (adjusted prevalence risk ratio = 3.63; 95% confidence interval: 1.38, 9.54; P = 0.009) by the Queensland Mental Health Court. CONCLUSIONS: Severity of cognitive disability is associated with determinations of unfitness but does not predict determinations of unsoundness in the Queensland Mental Health Court. Psychiatric assessments of cognitive impairment play a pivotal role in mental health court determinations for people with cognitive disability.

Intellectual disability and patient activation after release from prison: a prospective cohort study.

BACKGROUND: Intellectual disability and patient activation may be important drivers of inequities in health service access and health outcomes for people with intellectual disability transitioning from prison to the community. We assessed the association between intellectual disability and patient activation after prison release and examined whether this association varied, depending on whether intellectual disability was identified prior to prison release. METHODS: Overall, 936 prisoners were screened for intellectual disability by using the Hayes Ability Screening Index and completed the Patient Activation Measure (PAM) within 6 weeks of prison release and again at 1, 3 and 6 months post-release. We estimated the association between intellectual disability status and PAM scores by using a multilevel linear model, adjusting for sociodemographic, behavioural, health and criminogenic factors. We used propensity score matching to estimate the impact of being identified with intellectual disability prior to release from prison on the change in mean PAM score after prison release. RESULTS: Compared with those who screened negative for intellectual disability, ex-prisoners who screened positive, both with and without prior identification of intellectual disability, had significantly decreased mean PAM scores [(B = -4.3; 95% CI: -6.3, -2.4) and (B = -4.5; 95% CI: -6.8, -2.3), respectively] over 6 months of follow-up. Among those who reported being identified with intellectual disability prior to release from prison, a significant increase in PAM score at the 6-month follow-up interview (B = 5.89; 95% CI: 2.35, 9.42; P = 0.001) was attributable to being identified with intellectual disability prior to release. CONCLUSIONS: Ex-prisoners screening positive for possible intellectual disability have decreased patient activation for at least 6 months after release from prison. However, individuals whose possible intellectual disability is unidentified appear to be particularly vulnerable. Incarceration is a pivotal opportunity for the identification of intellectual disability and for initiating transitional linkages to health and intellectual disability-specific community services for this marginalised population.

Anomalous Broadening in Driven Dissipative Rydberg Systems.

We observe interaction-induced broadening of the two-photon 5s-18s transition in ^{87}Rb atoms trapped in a 3D optical lattice. The measured linewidth increases by nearly 2 orders of magnitude with increasing atomic density and excitation strength, with corresponding suppression of resonant scattering and enhancement of off-resonant scattering. We attribute the increased linewidth to resonant dipole-dipole interactions of 18s atoms with blackbody induced population in nearby np states. Over a range of initial atomic densities and excitation strengths, the transition width is described by a single function of the steady-state density of Rydberg atoms, and the observed resonant excitation rate corresponds to that of a two-level system with the measured, rather than natural, linewidth. The broadening mechanism observed here is likely to have negative implications for many proposals with coherently interacting Rydberg atoms.

Inter-rater reliability of the Hayes Ability Screening Index in a sample of Australian prisoners.

BACKGROUND: Reliable ascertainment of intellectual disability (ID) is important to identify those with special needs, in order for those needs to be met in the criminal justice system. Although the Hayes Ability Screening Index (HASI) is valid and widely used for the identification of possible ID, the risk of inter-rater bias between researchers when scoring the HASI has not yet been established. The current paper estimates the inter-rater reliability of the HASI in a sample of Indigenous and non-Indigenous prisoners in Western Australia. METHODS: We estimated intra-class correlation coefficients (ICC) for the consistency of agreement among three blinded raters using a two-way random-effects model assessing the inter-rater agreement of the HASI. Kappa was also estimated for the dichotomous HASI screening threshold outcome between the raters. RESULTS: The HASI exhibited very good within-subject consistency of agreement for Section B (ICC = 0.95; 95%CI:0.94-0.96), Section C (ICC = 0.97; 95%CI: 0.96-0.98) and Section D (ICC = 0.90; 95%CI: 0.87-0.92) subscales and for the total scaled score (ICC = 0.97; 95%CI: 0.96-0.98). The inter-rater reliability of the dichotomous adult ID screening threshold (<85) was also very good (Kappa = 0.95). CONCLUSIONS: The current study provides new evidence that the HASI has a low risk of bias from between-rater scoring and can be reliably scored by both non-clinicians and clinicians with little training, when administered in prison settings. Pre-scoring training should focus on the more subjective 'clock-drawing' section, in order to maximise inter-rater reliability.

Impact of dual diagnosis on healthcare and criminal justice costs after release from Queensland prisons: a prospective cohort study.

BACKGROUND: People released from prison have poorer health than the general public, with a particularly high prevalence of mental illness and harmful substance use. High-frequency use of hospital-based services is costly, and greater investment in transitional support and primary care services to improve the health of people leaving prison may therefore be cost-effective. METHODS: A prospective cohort study of 1303 men and women released from prisons in Queensland, Australia, between 2008 and 2010, using linked data was performed. We calculated healthcare costs and the cost of re-incarceration. We compared healthcare costs to the general public, and assessed the impact of past mental illness, substance use disorder, and dual diagnosis on both healthcare and criminal justice costs. RESULTS: Healthcare costs among the cohort were 2.1-fold higher than expected based on costs among the public. Dual diagnosis was associated with 3.5-fold higher healthcare costs (95% CI 2.6-4.6) and 2.8-fold higher re-incarceration costs (95% CI 1.6-5.0), compared with no past diagnosis of either mental illness or substance use disorder. CONCLUSIONS: People released from prison incur high healthcare costs, primarily due to high rates of engagement with emergency health services and hospital admissions. Comorbid mental illness and substance use disorders are associated with high health and criminal justice costs among people recently released from prison.

Discrimination experienced by sexual minority males in Australia: Associations with suicidal ideation and depressive symptoms.

INTRODUCTION: Discrimination has been under-examined as a social determinant of the higher rates of poor mental health experienced by sexual minorities. The objectives of our study were to: 1) assess whether discrimination was independently associated with poor mental health among sexual minority males, and 2) assess the potential mediation role of discrimination in the associations between sexual minority status and poor mental health. METHODS: We used cross-sectional data on 13,230 males aged 18-55 years from the Australian Longitudinal Study on Male Health; bisexual and homosexual males comprised 1.5% and 1.6% of the sample, respectively. We fit Poisson regression and zero-inflated negative binomial regression models to examine suicidality, depressive symptoms and perceived discrimination in the past two years as correlates of suicidality and depressive symptoms. RESULTS: Statistically significant differences were observed in the prevalence of perceived discrimination by sexual orientation (p < 0.001), with the highest prevalence among bisexual (29.3%) and homosexual (40.4%) males, and the lowest prevalence among heterosexual males (18.6%). After adjusting for confounding, bisexual/homosexual males had higher rates of perceived discrimination (IRR = 1.88, p < 0.001), recent suicidal ideation (IRR = 1.51, p = 0.008), lifetime suicide attempt (IRR = 2.09, p < 0.001) and recent depressive symptoms (IRR = 1.34, p < 0.001) than heterosexual males. Analysis of ß-coefficients suggested that discrimination may mediate a small to moderate proportion of the association between sexual minority status and poor mental health. LIMITATIONS: Use of cross-sectional data. CONCLUSION: Poor mental health is more common among sexual minority males, and discrimination may be a contributor to these mental health disparities. Reducing discrimination should be considered as part of a strategy to improve the mental wellbeing of sexual minority males.

The Mortality After Release from Incarceration Consortium (MARIC): Protocol for a multi-national, individual participant data meta-analysis.

INTRODUCTION: More than 30 million adults are released from incarceration globally each year. Many experience complex physical and mental health problems, and are at markedly increased risk of preventable mortality. Despite this, evidence regarding the global epidemiology of mortality following release from incarceration is insufficient to inform the development of targeted, evidence-based responses. Many previous studies have suffered from inadequate power and poor precision, and even large studies have limited capacity to disaggregate data by specific causes of death, sub-populations or time since release to answer questions of clinical and public health relevance. OBJECTIVES: To comprehensively document the incidence, timing, causes and risk factors for mortality in adults released from prison. METHODS: We created the Mortality After Release from Incarceration Consortium (MARIC), a multi-disciplinary collaboration representing 29 cohorts of adults who have experienced incarceration from 11 countries. Findings across cohorts will be analysed using a two-step, individual participant data meta-analysis methodology. RESULTS: The combined sample includes 1,337,993 individuals (89% male), with 75,795 deaths recorded over 9,191,393 person-years of follow-up. CONCLUSIONS: The consortium represents an important advancement in the field, bringing international attention to this problem. It will provide internationally relevant evidence to guide policymakers and clinicians in reducing preventable deaths in this marginalized population. KEY WORDS: Mortality; incarceration; prison; release; individual participant data meta-analysis; consortium; cohort.

Modifiable risk factors for external cause mortality after release from prison: a nested case-control study.

AIM: People released from prison are at higher risk of mortality from potentially preventable causes than their peers in the general population. Because most studies of this phenomenon are reliant on registry data, there is little health and behavioural information available on those at risk, hampering the development of targeted, evidence-based preventive responses. Our aim was to identify modifiable risk and protective factors for external cause and cause-specific mortality after release from prison. METHODS: We undertook a nested case-control study using data from a larger retrospective cohort study of mortality after release from prison in Queensland, Australia between 1994 and 2007. Cases were 286 individuals who had died from external causes (drug overdose, suicide, transport accidents, or violence) matched with 286 controls on sex, Indigenous status, and release date. We extracted data from detention, case-management, and prison medical records. RESULTS: Factors associated with increased risk of external cause mortality included use of heroin and other opioids in the community [odds ratio (OR) = 2.20, 95% CI 1.41-3.43, p < 0.001], a prescription for antidepressants during the current prison sentence (OR = 1.94, 95% CI 1.02-3.67, p = 0.042), a history of problematic alcohol use in the community (OR = 1.54, 95% CI 1.05-2.26, p = 0.028), and having ever served two or more custodial sentences (OR = 1.51, 95% CI 1.01-2.25, p = 0.045). Being married (OR = 0.45, 95% CI 0.29-0.70, p < 0.001) was protective. Fewer predictors were associated with cause-specific mortality. CONCLUSIONS: We identified several behavioural, psychosocial, and clinical markers associated with mortality from preventable causes in people released from prison. Emerging evidence points to interventions that could be targeted at those at increased risk of external cause mortality. These include treatment and harm reduction programmes (for substance use), improving transitional support programmes and continuity of care (for mental health), diversion and drug reform (for repeat incarceration) and nurturing stable relationships during incarceration. The period of imprisonment and shortly after release provides a unique opportunity to improve the long-term health of ex-prisoners and overcome the disadvantage associated with imprisonment.

Intracellular localization of the heat shock protein, HSP110, in Xenopus laevis A6 kidney epithelial cells.

Heat shock protein 110 (HSP110) is a large molecular mass chaperone that is part of the HSP70/DnaK superfamily. In the present study, we examined the accumulation of HSP110 in Xenopus laevis A6 kidney epithelial cells. Immunoblot analysis, using a homologous antibody, detected the presence of HSP110 in A6 cells maintained at 22 degrees C. The relative levels of HSP110 accumulation increased after heat shock or sodium arsenite treatment. Immunocytochemical analysis revealed that constitutively expressed HSP110 was localized in the cytoplasm in a diffuse granular pattern with enrichment in the nucleus. In A6 cells heat shocked at 33 degrees C or 35 degrees C for 2 to 4 h, HSP110 accumulation was enhanced and detected primarily in the cytoplasm as thread- or spindle-like structures. In contrast, HSP30 was not detected constitutively and heat shock treatment of A6 cells induced a relatively uniform punctate pattern primarily in the cytoplasm. Also, treatment of A6 cells at 35 degrees C for 6 h resulted in the presence of HSP110 and HSP30 enriched in the nucleus of most cells. Finally, A6 cells treated with 25 microM sodium arsenite produced very dense HSP110 structures primarily in the cytoplasm while HSP30 was enriched in the cytoplasm in a granular pattern.

Attitudes towards seclusion and restraint in mental health settings: findings from a large, community-based survey of consumers, carers and mental health professionals.

AIMS: There are growing calls to reduce, and where possible eliminate, the use of seclusion and restraint in mental health settings, but the attitudes and beliefs of consumers, carers and mental health professionals towards these practices are not well understood. The aim of this study was to compare the attitudes of mental health service consumers, carers and mental health professionals towards seclusion and restraint in mental health settings. In particular, it aimed to explore beliefs regarding whether elimination of seclusion and restraint was desirable and possible. METHODS: In 2014, an online survey was developed and widely advertised in Australia via the National Mental Health Commission and through mental health networks. The survey adopted a mixed-methods design, including both quantitative and qualitative questions concerning participants' demographic details, the use of seclusion and restraint in practice and their views on strategies for reducing and eliminating these practices. RESULTS: In total 1150 survey responses were analysed. A large majority of participants believed that seclusion and restraint practices were likely to cause harm, breach human rights, compromise trust and potentially cause or trigger past trauma. Consumers were more likely than professionals to view these practices as harmful. The vast majority of participants believed that it was both desirable and feasible to eliminate mechanical restraint. Many participants, particularly professionals, believed that seclusion and some forms of restraint were likely to produce some benefits, including increasing consumer safety, increasing the safety of staff and others and setting behavioural boundaries. CONCLUSIONS: There was strong agreement across participant groups that the use of seclusion and restraint is harmful, breaches human rights and compromises the therapeutic relationship and trust between mental health service providers and those who experience these restrictive practices. However, some benefits were also identified, particularly by professionals. Participants had mixed views regarding the feasibility and desirability of eliminating these practices.

Emergent equilibrium in many-body optical bistability.

Many-body systems constructed of quantum-optical building blocks can now be realized in experimental platforms ranging from exciton-polariton fluids to ultracold Rydberg gases, establishing a fascinating interface between traditional many-body physics and the driven-dissipative, nonequilibrium setting of cavity QED. At this interface, the standard techniques and intuitions of both fields are called into question, obscuring issues as fundamental as the role of fluctuations, dimensionality, and symmetry on the nature of collective behavior and phase transitions. Here, we study the driven-dissipative Bose-Hubbard model, a minimal description of numerous atomic, optical, and solid-state systems in which particle loss is countered by coherent driving. Despite being a lattice version of optical bistability, a foundational and patently nonequilibrium model of cavity QED, the steady state possesses an emergent equilibrium description in terms of a classical Ising model. We establish this picture by making new connections between traditional techniques from many-body physics (functional integrals) and quantum optics (the system-size expansion). To lowest order in a controlled expansion-organized around the experimentally relevant limit of weak interactions-the full quantum dynamics reduces to nonequilibrium Langevin equations, which support a phase transition described by model A of the Hohenberg-Halperin classification. Numerical simulations of the Langevin equations corroborate this picture, revealing that canonical behavior associated with the Ising model manifests readily in simple experimental observables.

Cultured mouse mammary epithelial cells: normal phenotype after implantation.

Mammary epithelial cells from normal virgin BALB/c mice were cultivated in vitro by the feeder cell technique developed and reported previously. These cells were cultured up to the 10th passage, equivalent to 60 cell divisions in culture. They were then tested for normality by several criteria, namely, the ability to regrow into normal mammary glands after implantation into cleared mammary fat pads of both syngeneic and nude mice, chromosome numbers, and response to mammogenic hormones. The cultured cells did form normal mammary ducts after implantation. The fraction of fat pads with ductal outgrowths as well as the size of the outgrowths was proportional to the number of cells implanted. When 10(6) cells were implanted into BALB/c mice, 83% of the fat pads contained outgrowths, filling, on the average, approximately 87% of the fat pad. More ductal outgrowths occurred from implanted cells taken from lower tissue culture passages than from high ones, and the number of outgrowths was greater in BALB/c mice than in nude mice. A small fraction of the cells in culture reacted with antibodies to casein, but there was no evidence of alpha-lactalbumin in the cells. However, ductal outgrowths from implanted cells responded to hormone stimulation of an estrogen deoxycorticosteroid pellet by forming well-developed lobulo-alveolar structures characteristic of pregnancy. Of the cells that were studied in passages 3 and 7, 85% were diploid. An abnormally growing culture in passage 10 was composed of cells in the tetraploid range. These tetraploid cells formed normal mammary ducts when implanted into animals.

Resumption of injecting drug use following release from prison in Australia.

INTRODUCTION: Ex-prisoners with a history of injecting drug use (IDU) experience disproportionate drug-related harm. Rapid resumption of substance use following prison release is common and evidenced in high rates of overdose mortality. However, few studies have documented the rate of IDU resumption following prison release or identified risk factors for relapse. METHODS: Structured interviews were conducted with 533 adults with a history of IDU in Queensland, Australia prior to release from prison and approximately 1, 3 and 6 months post-release. Incidence of self-reported IDU resumption was calculated overall and for each follow-up interval. Risk factors associated with time to resumption of IDU were estimated using discrete-time survival analysis. RESULTS: IDU resumption was reported by 41% of participants during a median of 98days of follow-up (IQR=94-121), an overall crude incidence of 1.06 per person-year. The highest rate was observed in the first month (23%; crude incidence 2.24 per person-year). In adjusted discrete-time survival analyses, being unemployed at the previous interview (AHR=1.59; 95%CI:1.10-2.30), shorter incarceration (≤90days vs. >365days; AHR=2.20; 95%CI:1.33-3.65), and IDU during the index incarceration (AHR=2.80; 95%CI:1.92-4.09) were significantly associated with time to IDU resumption; parole was protective (AHR=0.66; 95%CI:0.47-0.92). CONCLUSIONS: Evidence-based efforts to prevent IDU in prison and IDU resumption after release are important for both prisoner and public health. Enhancing opportunities for employment and capitalising on the short-term benefits of parole for ex-prisoners may delay resumption of IDU after release from prison. These strategies should complement rather than replace harm reduction efforts for this high-risk population.

Granulomatous interstitial pneumonia in a miniature swine associated with repeated intravenous injections of Tc-99m human serum albumin: concise communication.

Albumin lung-scanning agents have a proven high degree of safety, with the only contraindication to their use being allergic hypersensitivity. We have used these agents to investigate the physiologic effects of high Gz acceleratory forces on pulmonary perfusion using the miniature swine. Multiple doses of human macroaggregated albumin and human-albumin microspheres were given to a miniature swine at various levels of centrifugal acceleration over a 6-wk period. The dosages given were the same per kilogram as those used for routine clinical human studies. The animal subsequently died from a severe granulomatous interstitial pneumonia. The granulomatous lesions suggest that the pathogenesis may have involved a cell-mediated delayed hypersensitivity. This interstitial pneumonia may represent the end point in a chronic hypersensitivity response to the human-albumin lung-scanning agents.

Ethylene glycol monomethyl ether and propylene glycol monomethyl ether: metabolism, disposition, and subchronic inhalation toxicity studies.

Short-term and subchronic vapor inhalation studies have shown that there are pronounced differences in the toxicological properties of ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME). Overexposure to EGME has resulted in adverse effects on testes, bone marrow and lymphoid tissues in laboratory animals. PGME does not affect these tissues, and instead, overexposure to PGME has been associated with increases in liver weight and central nervous system depression. EGME is primarily oxidized to methoxyacetic acid in male rats, while PGME apparently undergoes O-demethylation to form propylene glycol. Since methoxyacetic acid has been shown to have the same spectrum of toxicity as EGME in male rats, the observed differences in the toxicological properties of EGME and PGME are thought to be due to the fact that the two materials are biotransformed via different routes to different types of metabolites.