Soft-tissue anatomy of the primates: phylogenetic analyses based on the muscles of the head, neck, pectoral region and upper limb, with notes on the evolution of these muscles

Apart from molecular data, nearly all the evidence used to study primate relationships comes from hard tissues. Here, we provide details of the first parsimony and Bayesian cladistic analyses of the order Primates based exclusively on muscle data. The most parsimonious tree obtained from the cladistic analysis of 166 characters taken from the head, neck, pectoral and upper limb musculature is fully congruent with the most recent evolutionary molecular tree of Primates. That is, this tree recovers not only the relationships among the major groups of primates, i.e. Strepsirrhini {Tarsiiformes [Platyrrhini (Cercopithecidae, Hominoidea)]}, but it also recovers the relationships within each of these inclusive groups. Of the 301 character state changes occurring in this tree, ca. 30% are non-homoplasic evolutionary transitions; within the 220 changes that are unambiguously optimized in the tree, ca. 15% are reversions. The trees obtained by using characters derived from the muscles of the head and neck are more similar to the most recent evolutionary molecular tree than are the trees obtained by using characters derived from the pectoral and upper limb muscles. It was recently argued that since the Pan/Homo split, chimpanzees accumulated more phenotypic adaptations than humans, but our results indicate that modern humans accumulated more muscle character state changes than chimpanzees, and that both these taxa accumulated more changes than gorillas. This overview of the evolution of the primate head, neck, pectoral and upper limb musculature suggests that the only muscle groups for which modern humans have more muscles than most other extant primates are the muscles of the face, larynx and forearm.

X-Ray Microscopy Of Multiphase Polymeric Materials

We have utilized the scanning transmission x-ray microscope at Brookhaven National Laboratory to acquire high energy resolution spectra of various polymers and to investigate the bulk characteristics of multiphasic polymeric materials with chemical sensitivity at a spatial resolution of about 50 nm. We present studies ranging from phase separated liquid crystalline polyesters and polyurethanes to various polymer blends. Improvements in the NEXAFS imaging and spectral acquisition protocol in the recent past provide much improved spectral fidelity and include in situ energy calibration with CO2.

The impact of light from computer monitors on melatonin levels in college students

OBJECTIVES

Self-luminous electronic devices emit optical radiation at short wavelengths, close to the peak sensitivity of melatonin suppression. Melatonin suppression resulting from exposure to light at night has been linked to increased risk for diseases. The impact of luminous cathode ray tube (CRT) computer monitors on melatonin suppression was investigated.

DESIGN

Twenty-one participants experienced three test conditions: 1) computer monitor only, 2) computer monitor viewed through goggles providing 40 lux of short-wavelength (blue; peak λ ≈ 470 nm) light at the cornea from light emitting diodes (LEDs), and 3) computer monitor viewed through orange-tinted safety glasses (optical radiation <525 nm ≈ 0). The blue-light goggles were used as a "true-positive" experimental condition to demonstrate protocol effectiveness; the same light treatment had been shown in a previous study to suppress nocturnal melatonin. The orange-tinted glasses served as a "dark" control condition because the short-wavelength radiation necessary for nocturnal melatonin suppression was eliminated. Saliva samples were collected from subjects at 23:00, before starting computer tasks, and again at midnight and 01:00 while performing computer tasks under all three experimental conditions.

RESULTS

Melatonin concentrations after exposure to the blue-light goggle experimental condition were significantly reduced compared to the dark control and to the computer monitor only conditions. Although not statistically significant, the mean melatonin concentration after exposure to the computer monitor only was reduced slightly relative to the dark control condition.

CONCLUSIONS

Additional empirical data should be collected to test the effectiveness of different, brighter and larger screens on melatonin suppression.

The pragmatic use of apomorphine at the end of life

Parkinson's Disease (PD) is an irreversible degenerative neurological disorder with no known cure. Apomorphine is a potent short-acting D1/D2 dopamine agonist administered sub-cutaneously that is used in the treatment of PD. Optimising PD medication is an important aspect of end of life care. There are no previously reported cases of apomorphine providing symptom relief in terminal care of PD patients. This case highlights its potential benefits for symptom control at the end of life.

Cranial base evolution within the hominin clade

The base of the cranium (i.e. the basioccipital, the sphenoid and the temporal bones) is of particular interest because it undergoes significant morphological change within the hominin clade, and because basicranial morphology features in several hominin species diagnoses. We use a parsimony analysis of published cranial and dental data to predict the cranial base morphology expected in the hypothetical last common ancestor of the Pan-Homo clade. We also predict the primitive condition of the cranial base for the hominin clade, and document the evolution of the cranial base within the major subclades within the hominin clade. This analysis suggests that cranial base morphology has continued to evolve in the hominin clade, both before and after the emergence of the genus Homo.

A d.c. magnetic metamaterial

Electromagnetic metamaterials are a class of materials that have been artificially structured on a subwavelength scale. They are currently the focus of a great deal of interest because they allow access to previously unrealizable properties such as a negative refractive index. Most metamaterial designs have so far been based on resonant elements, such as split rings, and research has concentrated on microwave frequencies and above. Here, we present the first experimental realization of a non-resonant metamaterial designed to operate at zero frequency. Our samples are based on a recently proposed template for an anisotropic magnetic metamaterial consisting of an array of superconducting plates. Magnetometry experiments show a strong, adjustable diamagnetic response when a field is applied perpendicular to the plates. We have calculated the corresponding effective permeability, which agrees well with theoretical predictions. Applications for this metamaterial may include non-intrusive screening of weak d.c. magnetic fields.

A pilot study of local injection of TNFerade biologic in addition to neo-adjuvant chemoradiation for the treatment of primary and recurrent rectal cancer

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Background: Rectal cancer presents unique therapeutic considerations due to competing concerns regarding sphincter preservation and local recurrence. Treatments using pre-operative chemoradiation are employed to decrease local recurrence and improve the probability of sphincter preservation. Agents, which improve the pathologic response rate may be of further benefit. Methods: TNFerade biologic is a replication deficient adenovirus expressing human TNF-alpha driven by a radiation inducible promoter. TNFerade biologic (4X10e10 pfu) is injected locally into rectal tumors once a week for 5 weeks. Patients receive concurrent chemoradiation utilizing oral capecitabene (937.50 mg/m2 BID, Monday-Friday) and external beam radiotherapy (1.8 Gy/day, 5 days per week to a total dose of 45 Gy). A boost dose of 5.4–9 Gy is delivered to sites of gross disease. After treatment, patients recover for 6–9 weeks before surgery. Patients are scored prior to the start of neo-adjuvant therapy for the feasibility of a sphincter preserving operation versus an abdominal perineal resection (APR). Following surgery the specimen (entire area submitted for processing) is examined for the percent of viable tumor remaining. The goal of the study is to show a target pathologic response rate of <10% viable tumor in more than 30% of patients treated. Results: Six patients have been treated (4M, 2F). There has been no toxicity attributable to the TNFerade biologic, and the chemoradiation has been well tolerated with only mild, expected toxicities. Five of the six patients have undergone surgery (one is awaiting surgery). Three of these five patients were thought to require an APR prior to treatment due to the size and location of their tumor. All five patients have successfully undergone sphincter- preserving operations. On examination of the five specimens, 3 had less than 5% viable tumor while 2 had greater than 50% viable tumor. All resections were margin negative. The target pathologic response rate of <10% viable tumor was achieved in 60% of the patients evaluated. Conclusion: The addition of TNFerade biologic to pre-operative chemoradiation was well tolerated and a prospective randomized trial comparing the addition of this agent to chemoradiation is warranted.

No significant financial relationships to disclose.

Metamaterials at zero frequency

We investigate the problem of designing metamaterial structures which operate at very low frequencies. As an example, we consider the case of a DC magnetic cloak, which requires a variable, anisotropic magnetic permeability with both paramagnetic and diamagnetic components. We show that a structure based on superconducting components is the key to diamagnetism at low frequencies, and present a metamaterial design which meets the requirements of the cloak.