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The challenge that large carnivores face in coexisting with humans calls into question their ability to carry out critical ecosystem functions such as mesopredator suppression outside protected areas. In this study, we examined the movements and fates of mesopredators and large carnivores across rural landscapes characterized by substantial human influences. Mesopredators shifted their movements toward areas with twofold-greater human influence in regions occupied by large carnivores, indicating that they perceived humans to be less of a threat. However, rather than shielding mesopredators, human-caused mortality was more than three times higher than large carnivore–caused mortality. Mesopredator suppression by apex predators may thus be amplified, rather than dampened, outside protected areas, because fear of large carnivores drives mesopredators into areas of even greater risk from human super predators.

Estimating habitat and spatial associations for wildlife is common across ecological studies and it is well known that individual traits can drive population dynamics and vice versa. Thus, it is commonly assumed that individual- and population-level data should represent the same underlying processes, but few studies have directly compared contemporaneous data representing these different perspectives. We evaluated the circumstances under which data collected from Lagrangian (individual-level) and Eulerian (population-level) perspectives could yield comparable inference to understand how scalable information is from the individual to the population. We used Global Positioning System (GPS) collar (Lagrangian) and camera trap (Eulerian) data for seven species collected simultaneously in eastern Washington (2018-2020) to compare inferences made from different survey perspectives. We fit the respective data streams to resource selection functions (RSFs) and occupancy models and compared estimated habitat- and space-use patterns for each species. Although previous studies have considered whether individual- and population-level data generated comparable information, ours is the first to make this comparison for multiple species simultaneously and to specifically ask whether inferences from the two perspectives differed depending on the focal species. We found general agreement between the predicted spatial distributions for most paired analyses, although specific habitat relationships differed. We hypothesize the discrepancies arose due to differences in statistical power associated with camera and GPS-collar sampling, as well as spatial mismatches in the data. Our research suggests data collected from individual-based sampling methods can capture coarse population-wide patterns for a diversity of species, but results differ when interpreting specific wildlife-habitat relationships.

Wildfires are increasing in size, frequency and severity due to climate change and fire suppression, but the direct and indirect effects on wildlife remain largely unresolved. Fire removes forest canopy, which can improve forage for ungulates but also reduce snow interception, leading to a deeper snowpack and potentially increased vulnerability to predation in winter. If ungulates exhibit predator-mediated foraging, burns should generally be selected for in summer to access high-quality forage and avoided in winter to reduce predation risk in deep snow. Fires also typically increase the amount of deadfall and initiate the growth of dense understory vegetation, creating obstacles that may confer a hunting advantage to stalking predators and a disadvantage to coursing predators. To minimize risk, ungulates may therefore avoid burns when and where stalking predators are most active, and use burns when and where coursing predators are most active. We used telemetry data from GPS-collared mule deer (Odocoileus hemionus), cougars (Puma concolor) and wolves (Canis lupus) to develop step selection functions to examine how mule deer navigated species-specific predation risk across a landscape in northern Washington, USA, that has experienced substantial wildfire activity during the past several decades. We considered a diverse array of wildfire impacts, accounting for both the severity of the fire and time since the burn (1-35 years) in our analyses. We observed support for the predator mediating foraging hypothesis: mule deer generally selected for burned areas in summer and avoided burns in winter. In addition, deer increased use of burned areas when and where wolf activity was high and avoided burns when and where cougar use was high in winter, suggesting the hunting mode of resident predators mediated the seasonal response of deer to burns. Deer were not more likely to die by predation in burned than in unburned areas, indicating that they adequately manage fire-induced changes to predation risk. As fire activity increases with climate change, our findings indicate the impact on ungulates will depend on trade-offs between enhanced summer forage and functionally reduced winter range, mediated by characteristics of the predator community.

Overlap between wildlife and human activity is key to causing wildlife-vehicle collisions, a globally pervasive and growing source of wildlife mortality.

Nitrogen deposition from air pollution is increasingly reaching alpine lakes where the addition of nitrate and ammonium to sensitive surface waters can cause acidification and/or eutrophication. Thirty years of sampling in the Wind River Range, WY, has shown some lakes increasing in nitrogen. We sought to (1) determine if nutrient concentrations in Deep Lake increase during snowmelt when atmospheric deposition is released from the snowpack and (2) assess if the sampling season, location, meteorological factors, and time of day samples are collected influence lake chemistry metrics, to inform monitoring. We analyzed water samples from the outlet of Deep Lake in peak snowmelt (June) and from the inlet, outlet, and middle of Deep Lake when the basin was snow free (August). In June, outlet samples were more acidic, and nitrogen content was three times August levels. Acid neutralizing capacity (ANC) declined with snowmelt. August inlet samples were higher in nutrients than outlet and mid-lake samples. Our results indicate that atmospheric pollution in the snowpack enters the lake with snowmelt. Although Deep Lake has not acidified, ANC levels indicate a risk of episodic acidification if nitrogen deposition continues to increase. When monitoring lakes at risk for episodic acidification, sampling during the late snowmelt pulse should be prioritized. Simplified sampling protocols may be used in some lakes, as epilimnion and outlet samples were nearly identical. The time of day and cloud cover did not affect lake chemistry, while wind speed and precipitation weakly increased August ANC and June pH, respectively.

Quantifying both the lethal and non-lethal (or “risk”) effects of predation has emerged as a major research focus in carnivore-ungulate systems. While numerous studies have examined predation risk and risk effects in recent decades, a lack of standardization in approaches has impeded progress in the field. We provide an overview of five major study design considerations involved in assessing predation risk and responses of prey in carnivore-ungulate systems, highlighting how different design choices can impact the strength and scope of inference. First, we stress the importance of distinguishing measures of predation risk (probability of being killed) from measures of risk effects (costs of antipredator behaviors in response to risk). Second, we recommend explicit consideration of spatial and temporal scales using a standardized framework to facilitate cross-study comparisons. Third, ungulates use visual, auditory, and olfactory sensory pathways to evaluate predation risk. Experiments that manipulate signals of risk (e.g., auditory playbacks or application of predator scent) can be powerful approaches, but the dosages and types of cues need to be carefully considered. Fourth, ungulates usually face threats from multiple predators simultaneously, and we highlight the potential for remote cameras and structural equation modeling to help address this challenge. Fifth, emerging technologies may substantially improve our ability to assess risk. We discuss several promising technologies, such as animal-borne video, unmanned aerial vehicles, and physiological sensors. We conclude with general recommendations for study design, which may improve the utility of predation risk research for the conservation and management of carnivore-ungulate systems.

from infectedblooddonorsintheUnitedStatesdemonstrate the need to improve and expedite current approaches for identifying donors at risk for emerging infectious diseases (EIDs). The safety of the US blood supply relies on accurate and timely data on risk factors, data evaluation, identifying potentially at-risk donors, and implementing appropriate interventions to reduce risk. Quantitative risk assessment (QRA) evaluates the risks and benefits of candidate blood safety interventions and relies on rapid data collection of donor risks. However, such data currently take several months to a year or more to collect, creating delays for responding to urgent public health threats. During the 2009 H1N1 influenza pandemic, the Centers for Disease Control and Prevention (CDC) emphasized the importance of temporarily deferring blood and plasma donors experiencing flu symptoms or not in good health at the time of donation. 5 More specific and sensitive screening methods rely on accurate donor exposure data.

A spin-aligner that shows ferromagnetism at room temperature is indispensable for spintronic applications. Diluted magnetic semiconductors are prospective candidates for a spin-aligner. We show that Cu-doped group-III nitrides show ferromagnetic behavior at room temperature although Cu is an intrinsic non-magnetic material. Problems with the building of magnetic secondary phases like in Mn- or Gd-doped nitrides are avoided by using Cu. The formation of Cu-group-III metal compounds is observed. However, these compounds will not affect the ferromagnetic properties and 90% of them can be removed by etching with HIVO 3 for 5 min.

Cu-alloyed GaN epilayers were prepared by plasma assisted molecular beam epitaxy with Cu-to-Ga beam equivalent pressure ratio of 1.2 to 4.8 %. Islands enriched with Cu were found on the GaN epitaxial layers grown in a Ga-rich environment. The islands are composed of a Cu9Ga4 intermetallic phase and GaN between which an orientation relationship was identified as [111]Cu9Ga4//[1 10]GaN and (10)Cu9Ga4//(0001)GaN. X-ray spectroscopy analyses indicated that the 1.2 % and 4.8 % samples contains 0.10 0.02 wt.%Cu and 0.04 0.03 wt.%Cu, respectively.

Beim femoroazetabularen Impingement (FAI) handelt es sich um ein neues, zunehmend an Akzeptanz gewinnendes mechanisches Konzept zur Entstehung der Koxarthrose. Dabei konnen sowohl die Deformitat der Hufte als auch ihre Nutzung zu Schaden fuhren. Man unterscheidet azetabulare (Pincer-) und femorale (Cam-)Deformitaten, welche zu charakteristischen Veranderungen des Pfannenrandes fuhren. Ein Cam-FAI wird v. a. bei aktiven 20- bis 30-jahrigen Mannern mit weit nach zentral reichenden Knorpelschaden, jedoch meist nur geringen Labrumschaden gesehen, wahrend das Pincer-FAI bei 30- bis 40-jahrigen Frauen, mit ausgepragten Labrumlasionen mit nur randstandiger Degeneration des azetabularen Knorpels gefunden wird. Impaktaktivitaten bei Arbeit oder Sport konnen bereits geringradige FAI-Deformitaten symptomatisch werden lassen. Obwohl fur einige FAI-Deformitaten die Ursachen bekannt sind, fehlt fur die Mehrzahl der Falle die Kenntnis der exakten Ursache. Ein besseres Verstandnis der Atiologie des FAI sowie deren Rolle in der Entstehung der Koxarthrose konnte es ermoglichen, die Pravalenz der sog. „primaren“ Koxarthrose und deren Folgen zu verringern.

The efficiency of the M. E. Muller acetabular roof reinforcement ring is documented on 141 patients with 150 operated hips since 1976 with a minimal clinically and radiologically follow-up of 6 years. The metal backing of the cup prevented cranial migration and protrusion almost completely. After 1982, when a bone bank with frozen femoral heads was established, the loss of bone stock was replaced with allograft, which can be fixed sufficiently with the reinforcement ring. In revision arthroplasty with bone stock of poor quality and quantity the acetabular roof reinforcement ring is a good method to reconstruct the acetabulum.

Thirty-seven operatively treated patients with residual acetabular dysplasia without arthritis had a labrum tear in the antero-lateral quadrant. A sensation of hip locking, or of a "dead leg" and episodes of "giving-way" were found to predict the presence of the tear. 95% of patients had an acute onset of pain. We treated the patients with a peri-acetabular osteotomy and in 12 cases the tear was repaired with a transosseous suture. We excised the labrum lesion in 21 cases with an extended avulsion from the bony rim and 4 tears were not severe enough to require attention. Twenty-two patients were available for a 4.5-year follow-up (range 2-8 years): 18 patients had no pain, 3 had mild pain and one had severe pain. Final pain outcome was not influenced by intraarticular treatment of the tear. The labrum tear is responsible for a well-defined clinical presentation of hip dysplasia and precedes secondary arthrosis. Early diagnosis helps to define the time to perform reconstructive surgery. The treatment consists of improving the coverage and stability of the femoral head by means of a multiplanar peri-acetabular osteotomy. The osteotomy unloads the torn fibrocartilage and allows it to heal by moving it out of the weight-bearing area.

In 1833, Chicago was a tiny backwoods settlement on the western frontier. It ranked as the world’s fourth largest city a century later. To celebrate the city’s remarkable rise, civic leaders and businessmen decided to host the city’s second world’s fair. The theme of this 1933–34 international exposition was “A Century of Progress.” Amazingly, in the midst of the Great Depression, this celebration championed corporate capitalism—the very culprit that many Americans blamed for their economic woes. The fair celebrated the advances of science and its application to consumer goods. Unlike earlier world’s fairs, this international venue de-emphasized the ...

Chronic irritation of the iliopsoas tendon is a rare cause of persistent pain after total joint replacement of the hip. In the majority of cases, pain results from a mechanical conflict between the iliopsoas tendon and the anterior edge of the acetabular cup after total hip arthroplasty. Pain can be reproduced by active flexion of the hip and by active raising of the straightened leg. In addition, painful leg raising against resistance and passive hyperextension are suggestive of an irritation of the iliopsoas tendon. Symptoms evolve from a mechanical irritation of the iliopsoas tendon and an oversized or retroverted acetabular cup, screws penetrating into the inner aspect of the ilium, or from bone cement protruding beyond the anterior acetabular rim. The diagnosis may be assumed on conventional radiographs and confirmed by CT scans. Fifteen patients with psoas irritation after total hip replacement are reported on. Eleven patients were treated surgically. The acetabular cup was revised and reoriented with more anteversion in six patients, isolated screws penetrating into the tendon were cut and leveled in three patients, and prominent bone cement in conflict with the tendon was resected once. A partial release of the iliopsoas tendon only was performed in another patient. Follow-up examination (range: 11-89 months) revealed that nine patients were free of pain and two patient had mild residual complaints. Psoas irritation in combination with total hip replacement can be prevented by a correct surgical technique, especially with proper selection of the cup size and insertion of the acetabular cup avoiding a rim position exceeding the level of the anterior acetabular rim.

Common understanding of residual hip dysplasia of the adult characterizes it as a uniform, anterolateral insufficiency of femoral head coverage; the proximal femur may or may not have increased valgus and antetorsion. This view is reflected by the parameters used for quantification but also by the classic surgical approaches to compensate or correct the deformity. More than two decades of dedication to hip dysplasia and its surgical treatment, but also the application of modern diagnostic tools such as magnetic resonance arthrography have allowed us to portray hip dysplasia more polymorphically showing a number of additional aspects with pathophysiologic, therapeutic and prognostic valence. The rim in acetabular dysplasia shows a variety of pathomorphologies ranging from hypertrophy and tearing of the labrum including fatigue fracture of the rim to degeneration with ganglion formation within the labrum, the capsule or the acetabular bone. Such rim pathology may explain sudden onset of pain but also influences the prognosis of joint preserving surgery. It is a rather new understanding that the acetabular morphology in hip dysplasia is not uniform. Pure lateral and pure anterior deficiency of coverage are small but interesting subgroups. Together with the frequent retroversion of the acetabulum these morphological and spatial aspects require special attention for a precise individual correction of the deformity. Finally, minor morphological abnormalities of the antero-lateral head-neck junction have been found to favor impingement after correction of the acetabulum. Knowledge of this problem has prompted a routine check of internal rotation in flexion during surgery and eventual arthrotomy and osteochondroplasty of the impinging site of the head and neck junction.

This study evaluates the application and limitations of the acetabular centre-edge angles as described by Wiberg (LCE) and Lequesne (VCA) in a group of adult patients with acetabular dysplasia that were treated with periacetabular osteotomy. Fifty hips in patients with a mean age of 30 years (range, 17–45) were identified and a number of radiographic indices were compared pre and post osteotomy. The potential for measurement variation in both the LCE and VCA angle was evaluated and relationships between the centre-edge angles and other radiographic indices were determined. While all hips displayed some degree of lateral deficiency only 19 (40%) of these cases displayed a “classic” lateral and anterior deficiency while 12 (20%) were in fact retroverted. The mean VCA in hips with primarily anterior and lateral deficiency (–6.7°±12.5) was significantly lower (p

Two proteins, which may be involved in DNA replication, have been isolated and characterized from the eukaryote Tetrahymena thermophila. One of these proteins, DNA polymerase, has been purified to apparent homogeneity. The enzyme has a native molecular weight of approximately 90 000 in the presence of salt and aggregates to higher-molecular-weight forms in the absence of salt. Purified preparations of the enzyme yield a major subunit of Mr 45 000 when the protein is analyzed by denaturing electrophoresis. Tetrahymena DNA polymerase requires a divalent cation for catalysis and prefers gapped template-primers over denatured and native DNAs. A template-primer such as poly(dT) . oligo(A) can also be elongated by the DNA polymerase. However, the enzyme will not use poly(A) . oligo(dT) as a template-primer. Sulfhydryl-blocking reagents, such as N-ethylmaleimide, inhibit Tetrahymena DNA polymerase. The DNA polymerase lacks assayable levels of both single and double-stranded deoxyribonuclease activity. Throughout the early stages of purification the DNA polymerase chromatographs together with a protein of molecular weight 100 000. This protein, which yields a single major polypeptide of Mr 25 000 when analyzed by denaturing electrophoresis, has single-stranded-DNA-binding properties and has the ability to stimulate both the rate and extent of DNA-polymerase-catalyzed DNA synthesis in vitro. By virtue of this latter ability, the protein has been referred to as the M (for 'modifying') protein. Maximum stimulation of DNA polymerase was achieved with template-primers, which contained large stretches of single-stranded template such as poly(dA) . (dT)10 mixed in a template-to-primer ratio of one to one. Stimulation of DNA polymerase activity by M protein in vitro appears to involve formation of longer product DNA.

Wahrend die Ursache der Gelenkschadigung bei der Huftdysplasie auf eine uberhohte axiale Belastung der Gelenkpfanne klar zuruckgefuhrt werden kann, ist die exakte Ursache der idiopathischen Koxarthrose bis heute nicht geklart. Basierend auf der Entwicklung einer chirurgischen Technik zur gefahrlosen chirurgischen Luxation der Hufte und der damit verbundenen Moglichkeit der intraoperativen Gelenkbeurteilung, fanden wir eine bewegungsinduzierte Schadigung, die peripher am Acetabulumrand beginnt und nach zentral fortschreitet. Dieses sog. "femoroacetabulare Impingement" (FAI), welches durch eine vermehrte acetabulare Uberdachung und/oder fehlende Spharizitat des Femurkopfes zu einem Anschlagen bzw. Einpressen des Femurkopfes in die Gelenkpfanne fuhrt, verursacht eine Schadigung des Labrum und/oder des Gelenkknorpels. Haufig kommt bei den bereits in der 2. und 3. Lebensdekade symptomatisch werdenden Patienten (Leistenschmerzen, reduzierte Innenrotation) eine vermehrte sportliche Aktivitat hinzu. Basierend darauf, ob die acetabulare oder femorale Pathologie dominiert, werden zwei verschiedene Typen des FAI, das Pincer- (Beiszangen-) und das Cam- (Nockenwellen-)FAI unterschieden. Neben diesen ossaren Alterationen tragen auch eine supraphysiologische Beweglichkeit sowie eine Uberbeanspruchung zum FAI bei. Das Impingement-Konzept hat zu einer Reihe neuer, mehrheitlich intrakapsularer Chirurgieansatze gefuhrt

The use of transgenic plants in the production of recombinant proteins for human therapy, including subunit vaccines, is being investigated to evaluate the efficacy and safety of these emerging biopharmaceutical products. We have previously shown that synthesis of recombinant glycoprotein B (gB) of human cytomegalovirus can be targeted to seeds of transgenic tobacco when directed by the rice glutelin 3 promoter, with gB retaining critical features of immunological reactivity (E.S. Tackaberry et al. 1999. Vaccine, 17: 3020–3029). Here, we report development of second generation transgenic plant lines (T1) homozygous for the transgene. Twenty progeny plants from two lines (A23T1-2 and A24T1-3) were grown underground in an environmentally contained mine shaft. Based on yields of gB in their seeds, the A23T1-2 line was then selected for scale-up in the same facility. Analyses of mature seeds by ELISA showed that gB specific activity in A23T1-2 seeds was over 30-fold greater than the best T0plants from the same transformation series, representing 1.07% total seed protein. These data demonstrate stable inheritance, an absence of transgene inactivation, and enhanced levels of gB expression in a homozygous second generation plant line. They also provide evidence for the suitability of using this environmentally secure facility to grow transgenic plants producing therapeutic biopharmaceuticals.Key words: transgenic tobacco seeds, homozygous second generation, glycoprotein B, human cytomegalovirus, vaccine, underground mine.

This manuscript contains a detailed description of the PHOBOS experiment as it is configured for the Year 2001 running period. It is capable of detecting charged particles over the full solid angle using a multiplicity detector and measuring identified charged particles near mid-rapidity in two spectrometer arms with opposite magnetic fields. Both of these components utilize silicon pad detectors for charged particle detection. The minimization of material between the collision vertex and the first layers of silicon detectors allows for the detection of charged particles with very low transverse momenta, which is a unique feature of the PHOBOS experiment. Additional detectors include a time-of-flight wall which extends the particle identification range for one spectrometer arm, as well as sets of scintillator paddle and Cherenkov detector arrays for event triggering and centrality selection.

We used laser Doppler flowmetry (LDF) with a high energy (20 mW) laser to measure perfusion of the femoral head intraoperatively in 32 hips. The surgical procedure was joint debridement requiring dislocation or subluxation of the hip. The laser probe was placed within the anterosuperior quadrant of the femoral head. Blood flow was monitored in specific positions of the hip before and after dislocation or subluxation. With the femoral head reduced, external rotation, both in extension and flexion, caused a reduction of blood flow. During subluxation or dislocation, it was impaired when the posterosuperior femoral neck was allowed to rest on the posterior acetabular rim. A pulsatile signal returned when the hip was reduced, or was taken out of extreme positions when dislocated. After the final reduction, the signal amplitudes were first slightly lower (12%) compared with the initial value but tended to be restored to the initial levels within 30 minutes. Most of the changes in the signal can be explained by compromise of the extraosseous branches of the medial femoral circumflex artery and are reversible. Our study shows that LDF provides proof for the clinical observation that perfusion of the femoral head is maintained after dislocation if specific surgical precautions are followed.

A plant based high fidelity vaccine production system is being developed with emphasis on producing antigens capable of being orally delivered in multivalent or subunit plant packets. Plant-based edible vaccines may provide an attractive, safe and inexpensive alternative to conventional vaccine production. Edible plant tissues are not normally antigenic in nature. However, foreign antigens from common infectious organisms like hepatitis-B virus (HBV) can be produced along with naturally occurring storage proteins in DNA-transformed plants. Upon administration via the oral route, these transgenic plant tissues may mobilize the protective humoral and mucosal immune responses to challenge the natural infectious agent. When tobacco, carrot and rice plants were transformed with the truncated version of the HBV nucleocapsid gene expression construct, non-infective hepatitis B viral core particles were observed via electron microscopy. A second plant codon-optimised HBV expression construct was designed that included the extensin signal sequence for augmented HBV particle accumulation. Upon transformation of tobacco plants with the codon-optimised construct, over 4 times more transgenic plants with high levels of expression of the HBV nucleocapsid protein were generated in comparison with a similar vector containing the unmodified wild-type HBV gene codon sequence. Further analysis via Western blotting confirmed the presence of the viral antigen in the total protein extracts from transgenic tobacco leaves and seeds. Electron microscopy showed that the expressed protein self-assembled into viral-like particles of 25–30 nm in diameter. To develop an edible subunit vaccine in plant seeds, a third plant transformation construct was used for the synthesis of the human cytomegalovirus glycoprotein B (HCMV gB) subunit. The gB protein derived from tobacco seeds retained critical structural features including epitopes for neutralizing antibodies and was targeted to the protein storage vesicles of tobacco seed endosperm. Two different strains of mice were orally immunized with tobacco seeds containing low concentrations of HCMV gB, with varying dosages, but without adjuvant. No anti-gB response was detected in intestinal or serum samples. However, a systemic immune response to normal tobacco seed proteins was observed in both strains of mice. While higher expression levels of antigens in seeds must be achieved, seeds may provide an effective and immunostimulatory vehicle for delivering edible vaccines to the intestinal mucosa. One of the outstanding challenges includes defining optimum conditions of antigen presentation, dosage and immunization schedules that will induce strong mucosal and/or systemic immune responses in heterogeneous populations. Here we review the different strategies being employed to produce specific oral antigens in plant tissues.

Human granulocyte-macrophage colony stimulating factor (GM-CSF), a cytokine with many applications in clinical medicine, was produced specifically in the seeds of transgenic tobacco plants. Two rice endosperm-specific glutelin promoters of different size and sequence, Gt1 and Gt3, were used to direct expression. Also in the Gt3 construct, the GM-CSF coding region was in fusion with the first 24 nucleotides of the mature rice glutelin sequence at its 5' end. With the Gt1 construct plants, seed extracts contained the recombinant human GM-CSF protein up to a level of 0.03% of total soluble protein. Transgenic seed extracts actively stimulated the growth of human TF-1 cells suggesting that the seed-produced GM-CSF alone and in fusion with the rice glutelin peptide was stable and biologically active. Furthermore, native tobacco seed extracts inhibited the activity of E. coli-derived GM-CSF in this cytokine-dependent cell line. The seeds of F1 generation plants retained the biological activity of human GM-CSF protein indicating that the human coding sequence was stably inherited. The feasibility of oral delivery of such stable seed-produced cytokines is discussed.

The early summer of 2000 saw the start of the RHIC experimental programme. The PHOBOS collaboration used data from the beginning of the running period to extract the first physics information about this exciting new regime. This first measurement consisted of pseudorapidity densities of primary charged particles near mid-rapidity in central Au + Au collisions at beam energies which gave centre-of-mass energies per pair of colliding nucleons of √snn = 56 and 130 GeV. The observed densities are higher than those observed previously in any collisions in the laboratory. In addition, the rate of increase in density between the two energies is significantly larger than that for nucleon-nucleon collisions at comparable beam energies. This paper will briefly describe the PHOBOS experiment (including the subset of the full detector installed for the early period of the RHIC beam), discuss the results of the first physics measurement and conclude with the prospects for the future, especially in the area of strangeness production.

Collisions of Au + Au have been studied at beam kinetic energies of 6.0, 8.0 and 10.8 GeV/nucleon at the AGS facility at Brookhaven National Laboratory. Particles emitted from the collisions were momentum analysed and identified in a magnetic spectrometer. Proton rapidity distributions are compared with those expected for isotropic emission from a stopped source and it is concluded that there is a substantial amount of transparency at all three beam energies even for the most central collisions. Strangeness production were studied via measurements of K, and spectra. All three indicate a strong enhancement of strangeness production relative to pp-collisions at similar centre-of-mass energies.