Conductivity Induced by High-Field Terahertz Waves in Dielectric Material.

An intense, subpicosecond, relativistic electron beam traversing a dielectric-lined waveguide generates very large amplitude electric fields at terahertz (THz) frequencies through the wakefield mechanism. In recent work employing this technique to accelerate charged particles, the generation of high-power, narrow-band THz radiation was demonstrated. The radiated waves contain fields with measured amplitude exceeding 2 GV/m, orders of magnitude greater than those available by other THz generation techniques at a narrow bandwidth. For fields approaching the GV/m level, a strong damping has been observed in SiO_{2}. This wave attenuation with an onset near 850 MV/m is consistent with changes to the conductivity of the dielectric lining and is characterized by a distinctive latching mechanism that is reversible on longer timescales. We describe the detailed measurements that serve to clarify the underlying physical mechanisms leading to strong field-induced damping of THz radiation (hω=1.59 meV, f=0.38 THz) in SiO_{2}, a bulk, wide band-gap (8.9 eV) dielectric.

Predicting career sector intent and the theory of planned behaviour: survey findings from Australian veterinary science students.

BACKGROUND: Producing graduates for a breadth of sectors is a priority for veterinary science programs. Undergraduate career intentions represent de-facto 'outcome' measures of admissions policy and curricula design, as intentions are strong predictors of eventual behaviour. Informed by Ajzen's Theory of Planned Behaviour, this study aimed to identify if contextually relevant attitudes and self-ratings affect student intentions for veterinary career sectors. RESULTS: Survey responses from 844 students enrolled in five Australian veterinary programs in 2014 were analysed. Intention was measured for biomedical research/academia, industry, laboratory animal medicine, public health/government/diagnostic laboratory services, mixed practice, intensive animal production, companion animal practice, not work in the veterinary profession, and business/entrepreneurship. Hierarchical multiple linear regression analysis enabled comparison of explanation of variance in intent by demographics, animal handling experience, species preference, and attitudes to aspects of veterinary work. Career sector intentions were highest for mixed or companion animal clinical practice, then business/entrepreneurship, then non-clinical sectors. Overall, intent was explained to a greater extent by species preferences than by animal experience, attitudes to aspects of veterinary work and demographics (with the exception of mixed practice intent) with gender having no significant effect. Several variables exerted negative effects on career intent for less popular career sectors. CONCLUSION: Ajzen's Theory of Planned Behaviour (TPB) provides a framework to increase understanding of and predict career sector intentions. Incorporation of attitude and self-efficacy measures in our study revealed preference for species types contributes greatly to career sector intentions for veterinary students, particularly for the more popular practice based sectors. Importantly, specific species preferences and other attitudes can have a negative effect on intent for non-aligned veterinary sectors. Further research is required to identify additional attitudes and/or beliefs to better explain variance in intent for less popular career sectors. Veterinary admissions processes may benefit from utilising the TPB framework. Identified effects revealed by this study may stimulate innovation in marketing, recruitment, admissions and curricular design, such as timing and role modelling, to utilise positive effects and mitigate against negative effects identified for sectors requiring greater representation of career intent in the student body.

Generation of Ramped Current Profiles in Relativistic Electron Beams Using Wakefields in Dielectric Structures.

Temporal pulse tailoring of charged-particle beams is essential to optimize efficiency in collinear wakefield acceleration schemes. In this Letter, we demonstrate a novel phase space manipulation method that employs a beam wakefield interaction in a dielectric structure, followed by bunch compression in a permanent magnet chicane, to longitudinally tailor the pulse shape of an electron beam. This compact, passive, approach was used to generate a nearly linearly ramped current profile in a relativistic electron beam experiment carried out at the Brookhaven National Laboratory Accelerator Test Facility. Here, we report on these experimental results including beam and wakefield diagnostics and pulse profile reconstruction techniques.

Measured Emittance Dependence on the Injection Method in Laser Plasma Accelerators.

Single-shot, charge-dependent emittance measurements of electron beams generated by a laser plasma accelerator (LPA) reveal that shock-induced density down-ramp injection produces beams with normalized emittances a factor of 2 smaller than beams produced via ionization injection. Such a comparison is made possible by the tunable LPA setup, which allows electron beams with nearly identical central energy and peak spectral charge density to be produced using the two distinct injection mechanisms. Parametric measurements of this type are essential for the development of LPA-based applications which ultimately require high charge density and low emittance.

External national validation of the Leicester Self-Assessment score for Type 2 diabetes using data from the English Longitudinal Study of Ageing.

AIMS: To validate the Leicester Self-Assessment score using a representative English dataset for detecting prevalent non-diabetic hyperglycaemia or undiagnosed Type 2 diabetes (defined as HbA1c ≥6.0%) and for identifying those who may go on to develop Type 2 diabetes within 10 years. METHODS: Data were taken from the English Longitudinal Study of Ageing, a nationally representative dataset of people aged ≥50 years. The area under the receiver-operator curve and performance metrics for the score at the recommended score threshold (≥16), were calculated for the outcomes of HbA1c ≥42 mmol/mol (6.0%) at baseline and self-reported Type 2 diabetes within 10 years in those aged 50-75 years at baseline. RESULTS: A total of 3203 individuals had a baseline HbA1c measurement, of whom 247 (7.7%) had an HbA1c concentration ≥42 mmol/mol (6.0%). The area under the receiver-operator curve was 69.4% (95% CI 66.0-72.9) for baseline HbA1c ≥42 mmol/mol. A total of 3550 individuals had diabetes status recorded at 10 years, of whom 324 (9.1%) were diagnosed with Type 2 diabetes within this time; the area under the receiver-operator curve for this outcome was 74.9% (95% CI 72.4-77.5). The score threshold of ≥16 had a sensitivity of 89.2% (95% CI 85.3-92.4) and a specificity of 42.3% (95% CI 40.5-44.0) for Type 2 diabetes within 10 years. CONCLUSIONS: The Leicester Self-Assessment score is validated for use across England to identify people with non-diabetic hyperglycaemia or undiagnosed Type 2 diabetes. Those with a high score are at high risk of developing diabetes in the future.

Levels and patterns of daily physical activity and sedentary behavior measured objectively in older care home residents in the United Kingdom.

BACKGROUND: Physical activity is important for maintaining independence and quality of life in older people living in care homes. Little is known about patterns of physical activity or sedentary behavior in this population. METHODS: Thirty-three care home residents (82.6 ± 9.2 years) wore an ActiGraph GTX3 accelerometer for seven days, which provided minutes of sedentary behavior and low, light, and moderate-to-vigorous physical activity. Participants undertook the Mini-Mental State Examination and care staff reported activities of daily living (Barthel index) and functional ambulation classification (FAC) for each participant. RESULTS: Participants spent on average 79% of their day sedentary, 14% in low, 6% in light, and 1% in moderate-to-vigorous physical activity. Activity levels did not significantly differ between days or hours of the day (P > .05). CONCLUSION: Levels of physical activity were very low and time being sedentary was high. This study can inform physical activity and sedentary behavior interventions for care homes' residents.

Planar-dielectric-wakefield accelerator structure using Bragg-reflector boundaries.

We report experimental measurements of narrow-band, single-mode excitation, and drive beam energy modulation, in a dielectric wakefield accelerating structure with planar geometry and Bragg-reflector boundaries. A short, relativistic electron beam (∼1 ps) with moderate charge (∼100 pC) is used to drive the wakefields in the structure. The fundamental mode of the structure is reinforced by constructive interference in the alternating dielectric layers at the boundary, and is characterized by the spectral analysis of the emitted coherent Cherenkov radiation signal. Data analysis shows a narrow-band peak at 210 GHz corresponding to the fundamental mode of the structure. Simulations in both 2D and 3D provide insight into the propagating fields and reproduction of the electron beams dynamics observables and emitted radiation characteristics.

Dielectric wakefield acceleration of a relativistic electron beam in a slab-symmetric dielectric lined waveguide.

We report first evidence of wakefield acceleration of a relativistic electron beam in a dielectric-lined slab-symmetric structure. The high energy tail of a ∼60 MeV electron beam was accelerated by ∼150 keV in a 2 cm-long, slab-symmetric SiO2 waveguide, with the acceleration or deceleration clearly visible due to the use of a beam with a bifurcated longitudinal distribution that serves to approximate a driver-witness beam pair. This split-bunch distribution is verified by longitudinal reconstruction analysis of the emitted coherent transition radiation. The dielectric waveguide structure is further characterized by spectral analysis of the emitted coherent Cherenkov radiation at THz frequencies, from a single electron bunch, and from a relativistic bunch train with spacing selectively tuned to the second longitudinal mode (TM02). Start-to-end simulation results reproduce aspects of the electron beam bifurcation dynamics, emitted THz radiation properties, and the observation of acceleration in the dielectric-lined, slab-symmetric waveguide.

The design and development of surgical templates for premolar transplants in adolescents.

The aim of designing and fabricating the surgical templates was to assist the surgical component of premolar transplantation, by establishing and replicating the root dimensions of the donor premolar tooth. The correct template could be used to assess the socket preparation (width and depth) prior to placement of the transplant in the recipient site, obviating the need to repeatedly try the donor tooth for fit at the recipient site, thereby minimising trauma to the periodontal ligament of the donor tooth. Seventy-five mandibular premolars and 50 maxillary second premolars were selected with varying stages of root development. All teeth had been extracted for orthodontic reasons. The root was measured for its length (maxL) and maximum (maxW) and minimum width (minW) with digital callipers from standardised reference points. These measurements were then used in the design of premolar transplant templates. The mean measurements for second maxillary premolars were maxL 14.6 mm (± 1.7), maxW 8.3 mm (± 0.5) and minW 4.9 (± 0.3). The mean measurements for mandibular premolars were maxL 14.8 (± 1.6), maxW 7.4 (± 0.6) and minW 5.3 (± 0.5). From these measurements, a range of maxillary second premolar and mandibular premolar templates have been fabricated. These figures also inform the multidisciplinary planning process for the space requirements at the donor site prior to transplantation.

Adolescent and Parent Preferences for Hypodontia: Discrete Choice Experiment.

Choosing hypodontia treatment requires young people and parents to consider a large amount of information, identify what is important to them, and make trade-offs between options. This study aimed to examine young people and parents' preferences for hypodontia treatment using discrete choice experiment (DCE). This was a cross-sectional survey of young people (12-16 y) with hypodontia of any severity, at any stage of treatment, and their parents. Participants were recruited from NHS Hospitals in England and Wales. A bespoke DCE questionnaire was developed to measure preferences for 6 attributes of hypodontia treatment (waiting time, treatment time, problems during treatment, discomfort during treatment, bite, appearance). The questionnaire was completed 1) online by young people and parents, individually or together, and 2) by child-parent dyads under observation. Preferences were analyzed using regression models. In total, 204 participants (122 young people, 56 parents, 26 dyads) completed the online questionnaire and 15 child-parent dyads completed the questionnaire under observation. The most important attribute in hypodontia treatment was improvement in appearance, but significant heterogeneity was found in preferences. Four distinct groups of participants were found: group 1 (39%): severe discomfort and problems were most important; group 2 (31%): most concerned about improvement in appearance of teeth and improvement in bite; group 3 (22%): appearance 3 times more important than any other attribute; and group 4 (9%): preferences difficult to interpret. There was variation in how child-parent dyads approached decision-making, with some negotiating joint preferences, while for others, one individual dominated. Making trade-offs in DCE tasks helped some people think about treatment and identify their preferences. Appearance is an important outcome from hypodontia treatment, but preferences vary and potential risks and functional outcome are also important to some people. There is a notable level of uncertainty in decision-making, which suggests further shared decision support would be valuable.

Effects of nanomaterials on luciferase with significant protection and increased enzyme activity observed for zinc oxide nanomaterials.

This principle goal of this research was to examine the effects of various nanomaterials on the activity and behavior of the firefly enzyme luciferase. Nanomaterials have been found to stabilize, and in some instances, shown to increase the activity of enzymes. In this study gold, manganese oxide (MnO), and zinc oxide (ZnO) nanomaterials were utilized in order to test their effects on enzyme activity. Luciferase was used because its activity is easy to analyze, as it typically produces a large amount of bioluminescence easily detected by a Microtiter plate reader. Following incubation with the various nanomaterials, luciferase was subjected to degradation by several protein denaturing agents, such as heat, SDS, urea, ethanol, protease, hydrogen peroxide, and pH changes. Results indicated that luciferase activity is indeed affected when combined with nanomaterials, accompanied by both increases and decreases in enzyme activity depending on the type of nanomaterial and denaturing agent used. In most of the experiments, when incubated with ZnO nanomaterials, luciferase depicted significant increases in activity and bioluminescence. Additional experiments, in which human A375 cells were treated with luciferase-nanomaterial mixtures, also depicted increased enzyme activity and bioluminescence for luciferase incubated with ZnO nanomaterials. Ultimately, our findings indicated that when luciferase was subjected to multiple types of denaturation, zinc oxide nanomaterials dramatically preserved and increased enzyme activity and bioluminescence.

Investigation of antirelaxation coatings for alkali-metal vapor cells using surface science techniques.

Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10 000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of C[Double Bond]C double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials.

Microaggressions towards people affected by mental health problems: a scoping review.

AIMS: This review aims to understand the scope of the literature regarding mental health-related microaggressions towards people affected by mental health problems. METHODS: A scoping review was conducted to explore this question. Four electronic health-oriented databases were searched alongside Google Scholar. As per scoping review principles, the inclusion criteria were developed iteratively. The results of included studies were synthesised using a basic narrative synthesis approach, utilising principles of thematic analysis and thematic synthesis where appropriate. RESULTS: A total of 1196 records were identified, of which 17 met inclusion criteria. Of these, 12 were peer-reviewed journal articles, three were research degree theses and two were book chapters. Six included empirical studies were qualitative, four were quantitative and two employed a mixed-methods design. Within these, five qualitative studies aimed to describe the nature of mental health microaggressions experienced by people with mental health problems. Themes identified in a thematic synthesis of these five studies included stereotypes about mental illness, invalidating peoples' experience and blaming people with mental illness for their condition. The included publications informed on the perpetration of mental health microaggressions by family, friends, health professionals and social workers. In addition, two studies created scales, which were then used in cross-sectional surveys of the general public and community members to assess characteristics, such as right-wing political views, associated with endorsement of mental health microaggressions. A consensus definition of microaggressions emerged from the included studies: microaggressions are brief, everyday slights, snubs or insults, that may be subtle or ambiguous, but communicate a negative message to a target person based on their membership of a marginalised group, in this case, people affected by mental illness. CONCLUSIONS: The study of mental health microaggressions is an emerging, heterogeneous field, embedded in the wider stigma and discrimination literature. It has been influenced by earlier work on racial microaggressions. Both can be ambiguous and contradictory, which creates difficulty defining the boundaries of the concept, but also underpins the key theoretical basis for the negative impact of microaggressions. Mental illness is a more concealable potential type of identity, so it follows that the reported perpetrators of microaggressions are largely friends, family and professionals. This has implications for intervening to reduce the impact of microaggressions. There are several challenges facing research in this area, and further work is needed to understand the impact of mental health microaggressions on people affected by mental health problems.

Prep1/Pbx2 complexes regulate CCL2 expression through the -2578 guanine polymorphism.

CC-chemokine ligand 2 (CCL2) is the major chemoattractant protein that recruits monocytes to sites of inflammation and increased expression of CCL2 is associated with numerous inflammatory diseases including human immunodeficiency virus-associated dementia (HIV-D). The -2578 guanine polymorphism in the CCL2 promoter has been associated with increased expression of CCL2 as well as pathogenesis of HIV-D; however, the molecular mechanism of regulation is unknown. We propose a molecular model for -2578 G-regulated CCL2 expression in astrocytes, which are major producers of CCL2 in the brain. The -2578 G polymorphism creates a consensus-binding site for the transcriptional regulator Prep1, which along with binding partner Pbx2, preferentially binds the -2578 G allele. CCL2 promoters harboring the G allele under unstimulated conditions exhibit a lower basal activity compared to the ancestral A allele. Upon interleukin-1 beta stimulation, Prep1/Pbx2 complexes maintain the ability to bind -2578 G alleles, yet transcription levels from promoters that harbor the A or G allele are equally activated, suggesting that the -2578 region does not influence CCL2 transcription under proinflammatory conditions. Therefore, promoters that harbor the -2578 G allele undergo a higher fold induction and by extension, individuals homozygous for -2578 G would be expected to exhibit hyper-responsive CCL2 phenotypes during periods of inflammation.

Eliciting Preferences in Dentistry with Multiattribute Stated Preference Methods: A Systematic Review.

BACKGROUND: Preference experiments are used to understand how patients and stakeholders value aspects of health care. These methods are gaining popularity in dentistry, but quality and breadth of use have not been evaluated. OBJECTIVES: To describe multiattribute stated preference experiment use in dentistry through illustration and critique of existing studies. DATA SOURCES: Systematic literature search of PubMed, Econlit and Ovid for Medline, Embase, PsychINFO, PsychARTICLES, and All EBM Reviews, as well as gray literature. STUDY ELIGIBILITY: Multiattribute stated preference experiments eliciting preferences for dental service delivery, treatments, and oral health states from the perspective of patients, the public, and dental professionals. Outcomes of interest were preference weights and marginal rates of substitution. Study selection was independently performed by 2 reviewers. APPRAISAL: Ten-point checklist published by the International Society of Pharmacoeconomics and Outcomes Research was used for quality assessment. SYNTHESIS: Descriptive analysis. RESULTS: Searches identified 12 records published between 1999 and 2015, mostly in nondental academic journals. Studies were undertaken in high-income countries in Europe and the United States. The studies aimed to elicit preference for service delivery, treatment, or oral health states from the perspective of the patients, dentists, or the public via discrete choice experiment methods. The quality scores for the studies ranged from 53% to 100%. LIMITATIONS: A detailed description and critique of stated preference methods are provided, but it was not possible to provide synthesized preference data. CONCLUSIONS: Multiattribute stated preference experiments are increasingly popular, but understanding the methods and outputs is essential for designing and interpreting preference studies to improve patient care. Patient preferences highlight important considerations for decision making during treatment planning. Valuation of health states and estimation of willingness-to-pay are important for resource planning and allocation and economic evaluation. Preference estimates and relative value of attributes for interventions and service delivery inform development and selection of treatments and services (PROSPERO 21.3.17: CRD42017059859). KNOWLEDGE TRANSFER STATEMENT: Understanding patient, professional, and public preferences is fundamental for evidence-based decision making and treatment delivery. Preference elicitation methods can be used to estimate the value given to health states, service delivery, individual treatments, and health outcomes. By describing and appraising the methodology and application of multiattribute stated preference experiments in dentistry, this review provides an essential first step to wider use of well-designed, high-quality preference elicitation methods.

Restoration of telomeres in human papillomavirus-immortalized human anogenital epithelial cells.

Loss of telomeres has been hypothesized to be important in cellular senescence and may play a role in carcinogenesis. In this study, we have measured telomere length in association with the immortalization and transformation of human cervical and foreskin epithelial cells by the human papillomavirus type 16 or 18 E6 and E7 open reading frames. By using a telomeric TTAGGG repeat probe, it was shown that the telomeres of precrisis normal and E6-, E7-, and E6/E7-expressing cells gradually shortened with passaging (30 to 100 bp per population doubling). Cells that expressed both E6 and E7 went through a crisis period and gave rise to immortalized lines. In contrast to precrisis cells, E6/E7-immortalized cells generally showed an increase in telomere length as they were passaged in culture, with some later passage lines having telomeres that were similar to or longer than the earliest-passage precrisis cells examined. No consistent association could be made between telomere length and tumorigenicity of cells in nude mice. However, of the three cell lines that grew in vivo, two had long telomeres, thus arguing against the hypothesis that cancer cells favor shortened telomeres. Our results indicate that arrest of telomere shortening may be important in human papillomavirus-associated immortalization and that restoration of telomere length may be advantageous to cells with regard to their ability to proliferate.

Would the introduction of the Index of Orthognathic Functional Treatment Need (IOFTN) affect referrals and acceptance of people for orthognathic treatment?

Introduction The Index of Orthognathic Functional Treatment Need (IOFTN) was developed to measure functional difficulties arising from malocclusions related to facial deformity. The IOFTN is not currently being used to determine suitability for orthognathic treatment, however, it is a useful aid for assessing and referring patients and takes into account functional and facial appearance. This paper aims to evaluate the potential impact of introduction of the IOFTN on the future provision of orthognathic services.Methods Two methods were used to consider the impact of the IOFTN on orthognathic provision. Firstly, a local retrospective audit was undertaken in Leeds Teaching Hospital NHS Trust involving thirty consecutively treated patients, for whom full records were retrieved. Data was collected using a standardised data caption form. Local standards were agreed concerning the need for treatment. Secondly, a systematic search of published studies was completed to assess evidence from across the UK.Results The audit standard, that is, 90% of patients treated with orthognathic surgery should be categorised as grade 4 (great need) or 5 (very great need) using the IOFTN, was fulfilled. The most common reason for seeking treatment related to dental and facial aesthetics and no patients were treated for speech or TMJ problems alone. The systematic review searches identified four suitable records for inclusion in the review, including two audits and two retrospective studies undertaken in secondary care settings across England and Scotland. These studies showed that at least 86% of all participants scored 4 or 5 using the IOFTN.Conclusions The findings from the audit and literature review indicate that referrals from general dentists and acceptance for orthognathic treatment in secondary care is unlikely to be significantly affected by introduction of the IOFTN. Referring dentists may find the IOFTN a useful prompt for determining whether people are suitable for orthognathic treatment.

On the attempts to measure water (and other volatiles) directly at the surface of a comet.

The Ptolemy instrument on the Philae lander (of the Rosetta space mission) was able to make measurements of the major volatiles, water, carbon monoxide and carbon dioxide, directly at the surface of comet 67P/Churyumov-Gerasimenko. We give some background to the mission and highlight those instruments that have already given insights into the notion of water in comets, and which will continue to do so as more results are either acquired or more fully interpreted. On the basis of our results, we show how comets may in fact be heterogeneous over their surface, and how surface measurements can be used in a quest to comprehend the daily cycles of processes that affect the evolution of comets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.

Survey of Victorian small ruminant herds for mycoplasmas associated with contagious agalactia and molecular characterisation of Mycoplasma mycoides subspecies capri isolates from one herd.

OBJECTIVE: Regarded as one of the most expensive production diseases of dairy sheep and goats, contagious agalactia (CA) is caused by any of four agents: Mycoplasma agalactiae, M. mycoides subspecies capri (Mmc), M. capricolum subspecies capricolum (Mcc) and M. putrefaciens. Although CA is worldwide in distribution, it has not been reported in Australia, even though studies between the 1950s and 1980s isolated each agent from sheep or goats without any clinical signs associated with it. The aim of this study was to examine sheep and goats in Victoria, Australia, for the presence of CA-associated mycoplasmas and to investigate the evolutionary relationships of these isolates by comparing their genetic differences with their counterparts from other parts of the world. METHODS: A 3-year epidemiological survey of small ruminant populations in Victoria, Australia, was conducted for the presence of CA-associated mycoplasmas and the isolates obtained were genotyped by multilocus sequence typing (MLST). RESULTS: Mmc was the only CA-associated agent isolated from the 1358 samples analysed in the study, but was not associated with CA on the property where it was found. MLST analyses of Mmc strains revealed a distinct clustering of Australian isolates into a novel clade, with the closest relatives being strains from Europe. The distinct clustering is consistent with the absence of clinical disease in Australia. CONCLUSION: The isolation of Mmc indicates that this subspecies persists in Australian small ruminant populations. However, full genome sequencing and in vitro animal experimentation are needed to unequivocally demonstrate the avirulence of Australian strains.

Identity, release, and binding of mitochondrial-bound hexokinases in mammary glands and adenocarcinomas of lactating mice.

The mitochondrial-bound hexokinases (adenosine triphosphate:D-hexose 6-phosphotransferase) of mammary adenocarcinoma and of normal gland were compared in lactating C3H mice. Treatment of mitochondria isolated from both the normal and neoplastic tissue with 0.5 m NaCl or 0.1 mM glucose 0-phosphate effected the release of about 50% of the bound hexokinase. In the presence of magnesium ion, enzyme from either source attached to mitochondria from either tissue and in all combinations to the same extent. Identification of the isoenzyme complement in the mitochondrial extract by diethylaminoethylcellulose chromatography revealed only types I and II. In the tumor, the hexokinase activity in both the cytosol and the fraction solubilized from mitochondria was predominantly in the form of type I ( 60%). In contrast, the activity released from mitochondria isolated from normal gland was predominately type II, while the cytosol contained almost equivalent amounts of types I and II. While this difference does not explain differences in glucose utilization between the normal and neoplastic tissue, it may provide a means of distinguishing between the two.