bluuebunny/crossref_metadata_2025 huggingface dataset:
First direct evidence of infanticide and cannibalism in wild snub‐nosed monkeys (Rhinopithecus bieti)
Authors: Xiang Zuo‐fu , Grueter Cyril C.
Published: December 2006

Although infanticide has been witnessed in many species of Colobinae, and a case was observed in a captive group of golden snub‐nosed monkeys (Rhinopithecus roxellana), observed cases of infanticide in wild snub‐nosed monkeys (Rhinopithecus spp.) have not previously been recorded. Here we describe the killing of a 1‐month‐old infant by a male in a black‐and‐white snub‐nosed monkey (R. bieti) group at Xiaochangdu in Tibet. The infanticidal attack was witnessed as part of a long‐term observational study of ecology and behavior that began in June 2003. The male was observed killing and eating the infant. The literature proposes three main explanations for infanticide: two adaptive hypotheses (sexual selection and resource competition), and one nonadaptive hypothesis (social pathology). Individual cases of infanticide, such as this one, are important for comparative purposes, but when examined on their own they are difficult to interpret in relation to established theoretical frameworks. The cases we describe here show some consistency with the sexual selection hypothesis, but the lack of critical information (i.e., as to paternity) makes it impossible to draw a firm conclusion. This is also the first described case of cannibalism in snub‐nosed monkeys. Am. J. Primatol. 69:1–6, 2007. © 2006 Wiley‐Liss, Inc.
Age and seasonal effects on predator‐sensitive foraging in squirrel monkeys (Saimiri sciureus): a field experiment
Authors: Stone Anita I.
Published: December 2006

A field experiment was conducted to examine the effect of perceived predation risk on the use of foraging areas by juvenile and adult primates under different conditions of local food abundance. Wild squirrel monkeys, Saimiri sciureus, were observed in an experiment conducted during the dry and the wet seasons at a site in Eastern Amazonia, Brazil. Animals were presented with feeding platforms that differed in food quantity and exposure to aerial predators through varying vegetative cover. In the dry season, juveniles and adults chose platforms based solely on food quantity. However, in the wet season, juveniles foraged preferentially on high‐reward platforms only if cover level also was high (i.e., potentially offered greater concealment from predators). In contrast, adults showed the same pattern of platform use regardless of season. These results indicate that age and local resource availability based on seasonality affect whether primates forage in a predator‐sensitive manner. Juveniles may be more sensitive to predation risk when foraging, and individuals may take fewer risks when resource abundance is high in their environment. Am. J. Primatol. 69:1–15, 2007. © 2006 Wiley‐Liss, Inc.
Responses of squirrel monkeys to seasonal changes in food availability in an eastern Amazonian forest
Authors: Stone Anita I.
Published: December 2006

Tropical forests are characterized by marked temporal and spatial variation in productivity, and many primates face foraging problems associated with seasonal shifts in fruit availability. In this study, I examined seasonal changes in diet and foraging behaviors of two groups of squirrel monkeys (Saimiri sciureus), studied for 12 months in Eastern Brazilian Amazonia, an area characterized by seasonal rainfall. Squirrel monkeys were primarily insectivorous (79% of feeding and foraging time), with fruit consumption highest during the rainy season. Although monkeys fed from 68 plant species, fruit of Attalea maripa palms accounted for 28% of annual fruit‐feeding records. Dietary shifts in the dry season were correlated with a decline in ripe A. maripa fruits. Despite pronounced seasonal variation in rainfall and fruit abundance, foraging efficiency, travel time, and distance traveled remained stable between seasons. Instead, squirrel monkeys at this Eastern Amazonian site primarily dealt with the seasonal decline in fruit by showing dietary flexibility. Consumption of insects, flowers, and exudates increased during the dry season. In particular, their foraging behavior at this time strongly resembled that of tamarins (Saguinus sp.) and consisted of heavy use of seed‐pod exudates and specialized foraging on large‐bodied orthopterans near the forest floor. Comparisons with squirrel monkeys at other locations indicate that, across their geographic range, Saimiri use a variety of behavioral tactics during reduced periods of fruit availability. Am. J. Primatol. 69:1–16, 2007. © 2006 Wiley‐Liss, Inc.
Within‐group female–female agonistic interactions in Taiwanese macaques (Macaca cyclopis)
Authors: Su Hsiu‐hui , Birky Wendy A.
Published: December 2006

Feeding‐related agonism among wild female Taiwanese macaques was investigated in two study groups at ecologically diverse sites (Fu‐shan and Ken‐ting) to determine whether contest‐feeding competition was present in these groups. Females that contest for food within a primate group are hypothesized to form dominance hierarchies and tend to be philopatric. In this study we tested 1) whether Taiwanese macaque females show higher agonism in a feeding context, 2) whether they exhibit stronger agonism over higher‐quality foods, and 3) whether higher agonism rates occur in smaller food patches. Female Taiwanese macaques at both study sites showed similar agonism rates in a feeding context (0.30 events/hr). They exhibited higher agonism rates inside food patches than outside food patches in the spring. Higher agonism rates occurred during seasons of higher fruit availability, and a lower agonism rate occurred in winter when the macaques switched to feeding on fallback foods. Females in the Fu‐shan group exhibited higher proportions of aggressive interactions over higher‐quality foods, such as animal matter and the reproductive parts of plants. In the Ken‐ting group, 95.8% of feeding‐related agonistic interactions among females occurred over fruits. Agonistic interactions that occurred in small food patches tended to result in the agonism recipient leaving the food patch. We conclude that female Taiwanese macaques show contest feeding competition in certain contexts. The patterns we observed have also been documented in other primate species in which females are philopatric and form linear dominance hierarchies. Am. J. Primatol. 69:1–13, 2007. © 2006 Wiley‐Liss, Inc.
Golden lion tamarin sleeping‐site use and pre‐retirement behavior during intense predation
Authors: Franklin Samuel P. , Hankerson Sarah J. , Baker Andrew J. , Dietz James M.
Published: December 2006

Sleeping sites, their patterns of use, and cryptic pre‐retirement behavior mitigate predation risk at sleeping sites and could influence prey fitness. We evaluated sleeping‐site usage for 10 groups of golden lion tamarins (GLTs) from a population that recently suffered a substantial decline due to predation at sleeping sites. We recorded the average number of nights that groups spent at their different sleeping sites to determine whether patterns of sleeping‐site use were influenced by predation risk, as measured by the rate of encounters with predators, or the availability of suitable sleeping sites, as measured by the size of a group's home range and amount of mature forest within their home range. In addition, we measured travel speed to sleeping sites and compared this speed with that recorded at other times of day. GLT groups spent more nights on average at each of their sleeping sites compared to other callitrichid species for which data are available. Predation risk and habitat characteristics were not significant predictors of how many times groups used each of their different sleeping sites. Groups significantly increased their travel speed just before entering the sleeping site. Rapid locomotion to secure tree cavities may help GLTs avoid crepuscular and nocturnal predators; however, we speculate that this strategy failed numerous GLTs in our study population during the previous decade because they used sleeping sites that were accessible to predators. Am. J. Primatol. 69:1–11, 2007. © 2006 Wiley‐Liss, Inc.
Exploring immature‐to‐mother social distances in Mexican mantled howler monkeys at Los Tuxtlas, Mexico
Authors: Arroyo‐Rodríguez Víctor , Serio‐Silva Juan carlos , Álamo‐García Javier , Ordano Mariano
Published: December 2006

We analyzed immature‐to‐mother social distance (juveniles and non‐nursing infants) in two Mexican mantled howler monkey (Alouatta palliata) troops inhabiting a tropical rainforest fragment (40 ha) at Los Tuxtlas, Veracruz, Mexico. During July and August of 2000 and 2001 we applied an instantaneous sampling method (317 hr) to record the behaviors of the immatures and their mothers, as well as distances (ordinal scale) between immatures and their mothers (IMD), and between immatures and nonmother individuals (INMD). Immatures were generally less than 5 m away from any individual of the troop. Social distance was influenced by the different behaviors of both mothers and immatures, with the shortest distances occurring during rest (IMD <5 m in 94% of all instantaneous samples) and the longest during exploration (21%≥10 m) and play (26%≥10 m). When IMD increased, we found a higher percentage of records <5 m to other individuals, particularly with the probable father. When the variation in distance to the mother and to other individuals in the troop was considered, the immature animals' distance to other troop members depended on the immatures' age and type of behavior. Overall, these results suggest that in this low‐activity species the development of the immature is associated with a complex set of relationships with other troop members. Am. J. Primatol. 69:1–9, 2007. © 2006 Wiley‐Liss, Inc.
Female dominance and feeding priority in a prosimian primate: experimental manipulation of feeding competition
Authors: White Frances J. , Overdorff Deborah J. , Keith‐Lucas Timothy , Rasmussen Michele A. , Eddie Kallam W. , Forward Zoë
Published: December 2006

Female dominance and feeding priority are considered unique behavioral strategies in many Malagasy lemuriformes, particularly Lemur catta. Two hypotheses have been introduced to explain these behavior patterns: 1) females are agonistically dominant over males to mitigate female–male food competition so that females can compensate for high energy demands and inefficient reproductive physiology, and 2) males defer to females when feeding as a reproductive strategy. We tested these hypotheses by conducting controlled feeding experiments on free‐ranging ring‐tailed lemurs (Lemur catta) on St. Catherine's Island, GA. Food was dispersed in three ways to simulate varying patch sizes. All feeding and agonistic interactions were recorded during each trial (n = 24). The degree of relatedness between individuals was determined using DNA fingerprinting. There was a clear relationship between food dispersion and both expression of female dominance and feeding priority. Elements of both hypotheses were supported because male and female L. catta used different strategies depending on rank and the dispersion of food. Interpretation of the impact of male rank was complicated because the younger, low‐ranking males had female relatives in the group. Females fed more than males, and rates of aggression decreased as food dispersion increased. High‐ranking, older unrelated males deferred to females and received little aggression. The top‐ranking male deferred the most and sired most if not all of the offspring. Low‐ranking, younger related males fought with females for access to food sources, received more aggression, and did not sire offspring. Am. J. Primatol. 69:1–10, 2007. © 2006 Wiley‐Liss, Inc.
Diademed sifakas (Propithecus diadema) use olfaction to forage for the inflorescences of subterranean parasitic plants (Balanophoraceae:Langsdorffiasp., and Cytinaceae:Cytinussp.)
Authors: Irwin Mitchell T. , Jean‐Luc Raharison Fanomezantsoa , Rakotoarimanana Harison , Razanadrakoto Edmond , Ranaivoson Edmond , Rakotofanala Justin , Randrianarimanana Charles
Published: December 2006

Primates usually locate food resources using visual cues and memory, yet the potential for olfactory‐guided (or olfactory‐assisted) food location remains relatively unexplored. Here we report observations of wildPropithecus diademathat strongly suggest that olfaction is used to locate the inflorescences of two subterranean parasitic plant species (Langsdorffiasp. andCytinussp.). These valued but seasonal food resources are found obscured in leaf litter, and sifakas spend considerable time on the ground engaged in what appears to be olfactory exploration before they locate the inflorescences. Because they are visually obscured and occur within a substrate that is rarely used by sifakas, accidental discovery of these resources seems unlikely. Individuals may learn to exploit them by watching conspecifics. Am. J. Primatol. 69:1–6, 2007. © 2006 Wiley‐Liss, Inc.
Behavior and endocrine concentrations do not distinguish sex in monomorphic juvenile howlers (Alouatta palliata)
Authors: Clarke Margaret R. , Zucker Evan L. , Ford Randall T. , Harrison Richard M.
Published: December 2006

Behavioral observations on juvenile mantled howlers are limited by visually undifferentiated genitalia; however, animals can be sexed when they are very young or if they are captured. Behavioral data and fecal samples from juveniles during month‐long field studies from 1993 to 1995 were analyzed to determine whether there are developmental differences in behavior or hormone concentrations that can be used to differentiate males from females. The subjects were juveniles of known sex and age from five different social groups on Hacienda La Pacifica, Costa Rica. Based on 749.8 hr of focal‐animal sampling, there were no sex differences in daily activity patterns. There were no sex differences in proximity to mothers and other group members, and age differences reflected howler life‐history patterns. There were no differences in estradiol or testosterone concentration by age or sex. Juvenile monomorphy thus extends beyond morphology to behavioral and hormonal similarity as well. Most juveniles are forced out of their natal groups and remain solitary until they join new groups by supplanting all same‐sex adult group members. Monomorphy may allow them to spend more time in natal groups, and thus both reduce the solitary period and allow the juveniles to improve social skills needed for later immigration. While this strategy may benefit juvenile howlers, it remains a problem for those who wish to study juvenile sex differences from a distance. Am. J. Primatol. 69:1–8, 2007. © 2006 Wiley‐Liss, Inc.
Another gorilla (Gorilla gorilla gorilla) recognizes himself in a mirror
Authors: Posada Sandra , Colell Montserrat
Published: December 2006

Various attempts have been made to explain why gorillas (Gorilla gorilla gorilla) find it difficult to recognize their mirror image. One of the most oft‐cited reasons is aversion to eye contact, which stops gorillas from looking into a mirror and thus prevents them from carrying out a suitable exploration that could lead to self‐recognition. In the experimental design used here the subject was first habituated both to observers and to the mirror as an object before being exposed to the latter. The study was performed with a single subject who was well adapted to captivity and exhibited no aberrant behavior or signs of stress. The results revealed that the subject had no aversion to eye contact. He showed considerable interest in the mirror and appeared relaxed when faced with his image. He gave a positive response to the mark test. Am. J. Primatol. 69:576–583, 2007. © 2006 Wiley‐Liss, Inc.
Neuroendocrine regulation of prolactin secretion in adult female rhesus monkeys during different phases of the menstrual cycle: role of neuroexcitatory amino acid (NMA)
Authors: Jahan S. , Jalali S. , Shami S.A.
Published: December 2006

The present study attempts to examine the role of N‐methyl‐D, L‐aspartate (NMDA) receptors in the central regulation of prolactin (PRL) secretion, which may be involved in ovarian function and its alteration by glutamate in various phases of the menstrual cycle of female rhesus monkeys (Macaca mulatta). The results suggest that the glutaminergic component of the control system, which governs PRL secretion by utilizing NMDA receptors, may have an important role in regulating changes in PRL secretion. The response of PRL during the luteal phase of the cycle was different from that observed in follicular and menstrual phases. Steroids may influence the NMDA‐dependent drive to release PRL. N‐methyl‐D‐aspartic acid (NMA) involvement in the regulation of PRL secretion may occur through activation of the PRL‐stimulating system depending on the physiological state or steroidal milieu. It is possible, therefore, that the NMA‐induced release of PRL‐releasing factors (PRF) and PRL are enhanced in the presence of ovarian feedback. Am. J. Primatol. 69:1–12, 2007. © 2006 Wiley‐Liss, Inc.
Genital swellings in silvered langurs: what do they indicate?
Authors: Shelmidine Nichole , Borries Carola , Koenig Andreas
Published: December 2006

The occurrence of genital swellings was examined in adult female silvered langurs (Trachypithecus cristatus). In contrast to the exaggerated swellings found in cercopithecines and apes, genital swellings in silvered langurs are confined to the vulva and the surrounding perineum, but they may nevertheless convey information similar to that of exaggerated swellings (i.e., correlate with the receptive period and fertility). If so, genital swellings would be expected to occur most frequently in cycling females, and sexual behavior and male interest should most frequently involve females with swellings. Swellings during gestation, if they occur at all, should be most pronounced at the beginning. Swelling sizes (in three size categories) in nine adult females were examined throughout different reproductive states (cycling, pregnant, and lactating), and in relation to proceptivity, receptivity, and attractivity. Data were collected from November 2002 through March 2004 (on 500 of the 502 calendar days) at the Wildlife Conservation Society's Bronx Zoo. Female sexual behavior (proceptivity and receptivity) and male inspection (attractivity) were recorded each day for 6 hr by video camera (2,948 hr total) and analyzed as present or absent for each female day. Swellings were assessed directly (not from videotapes). In contrast to the predictions, swellings occurred significantly less frequently in cycling females (compared to pregnant females) and no regular, cyclic pattern could be detected. Some females conceived without a swelling. Female attractivity was independent of swellings but coincided with proceptive behavior. Swellings occurred most frequently in pregnant females, especially toward the end of the gestation period. Therefore, genital swellings in silvered langurs are not similar to exaggerated swellings or the smaller genital swellings that have been described for some other primates. It is currently not clear what they signal to conspecifics. Male behavior needs to be studied in more detail, and the hormonal basis for these swellings should be explored. Am. J. Primatol. 69:519–532, 2007. © 2006 Wiley‐Liss, Inc.
Genetic correlations between mandibular molar cusp areas in baboons
Authors: Hlusko Leslea J. , Do Nicholas , Mahaney Michael C.
Published: December 2006

Primate evolutionary studies rely significantly on dental variation given the large role that teeth play in how an organism interacts with its environment (animal and plant) and conspecifics. Variation in cusp size has been shown to vary among primate taxa, although most studies to date focused on extant and extinct hominoids. Here we test the assumed hypothesis that a significant proportion of this variation in baboons is due to the additive effects of genes. We perform quantitative genetic analyses on variation in two‐dimensional (2‐D) mandibular molar cusp size in a captive pedigreed breeding population of baboons (Papio hamadryas) from the Southwest National Primate Research Center. These analyses show that variation in cusp size is heritable and sexually dimorphic. Additionally, we tested for genetic correlations between cusps on the same crown, between morphological homologues along the tooth row, and between cusp area and crown buccolingual width. We find that four of the six cusp pairs on the first molar have a genetic correlation of one, save for the metaconid–hypoconid and entoconid–hypoconid, which are not statistically different from zero. The second and third molars have lower genetic correlations, although the metaconid–hypoconid correlation is similarly estimated at zero and the entoconid–protoconid correlation is estimated to be one. This cross pattern of genetic and no genetic correlation does not immediately accord with the known pattern of development and/or calcification. We propose two explanative hypotheses. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
Continuity or discontinuity of the life‐style in central Italy during the Roman imperial age‐early middle ages transition: Diet, health, and behavior
Authors: Belcastro Giovanna , Rastelli Elisa , Mariotti Valentina , Consiglio Chiara , Facchini Fiorenzo , Bonfiglioli Benedetta
Published: December 2006

Dento‐alveolar pathologies and alterations (dental wear, caries, abscesses, ante mortem tooth loss (AMTL), calculus, hypoplastic defects, and chipping) and skeletal markers of health (cribra orbitalia and periostitis) were analyzed in two skeletal samples from the necropolises of Quadrella (I–IV c. AD) and Vicenne‐Campochiaro (VII c. AD) in the Molise region of central Italy. The aim was to determine if the Roman Imperial Age‐Early Middle Ages transition characterized by political, socioeconomic, and cultural transformations affected the biology of these populations, particularly their alimentation and health status. The frequencies of caries and AMTL, similar in the two samples, suggest a high consumption of carbohydrates. The higher levels of heavy wear, calculus, and interproximal chipping in the Vicenne population indicate a greater use of fibrous foods (both meat and others), in line with the dietary model of Germanic peoples. Health conditions do not appear to have been good in either period, as shown by the high frequencies of linear hypoplasia and the presence of cribra orbitalia and periostitis. The diet of the individuals buried with horses of the Vicenne population did not differ from that of the rest of the population, whereas there were evident differences in the use of the teeth for nonmasticatory activities among these individuals. Therefore, from the point of view of alimentation and health status, the profound socioeconomic and cultural transformations during the Late Antiquity‐Early Middle Ages transition do not seem to have been translated into a true discontinuity of the two Molisan populations. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
An academic genealogy on the history of American field primatologists
Authors: Kelley Elizabeth A. , Sussman Robert W.
Published: December 2006

In this paper, we present the academic genealogy of American field primatologists. The genealogy has been compiled to formally document the historical record of this young field. Data have been collected from three main sources: 1) e‐mail surveys, 2) library and Internet research, and 3) verbal communication through forums such as American Association of Physical Anthropology meetings. Lineages of primatologists have been graphically displayed using Microsoft Visio. As of September 2005, 672 names and 239 affiliated universities, organizations and institutions have been recorded in 19 lineages. Five hundred and thirty‐eight of the 672 names, 80.1%, are field primatologists. The Hooton/Washburn lineage is the largest; 60.6% of the recorded field primatologists are linked to this lineage. In addition, four of the five professors who have mentored a comparable number of field primatologists at American universities since Washburn are linked to the Hooton/Washburn lineage; and the school where Washburn mentored a majority of his students, UC‐Berkeley, continues to have the highest overall graduation record for this subdiscipline. However, the field of primatology has been diversifying since the 1960s, and different universities are now responsible for graduating a substantial number of primatologists. We conclude that while the Hooton/Washburn lineage has remained remarkably homogenous in its anthropological focus, the field is also becoming increasingly enriched by primatologists who have had training in fields such as zoology, psychology, and ecology both in the United States and abroad. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
Forelimb segment length proportions in extant hominoids and Australopithecus afarensis
Authors: Drapeau Michelle S.M. , Ward Carol V.
Published: December 2006

Forelimb proportions have been used to infer locomotor adaptation in Australopithecus afarensis. However, little is known about proportions among individual forelimb segments in extant or fossil hominoids. The partial A. afarensis skeleton A.L. 438‐1 and the more complete skeleton A.L. 288‐1 provide the opportunity to assess relative length of the arm, forearm, wrist, and palm. We compare scaling relationships between pairs of forelimb bones of extant hominoids and A. afarensis, and length of individual forelimb elements to a body size surrogate. Hylobatids, and to a lesser extent orangutans, have the longest forelimb bones relative to size, although the carpus varies little among taxa, perhaps due to functional constraints of the wrist. Pan species are unique in having long metacarpals relative to ulnar length, demonstrating that they probably differ from the common chimp–human ancestor, and also that developmental mechanisms can be altered to results in differential growth of individual forelimb segments. A. afarensis has no forelimb bones that are significantly longer than those of humans for its size. It falls within the range of variation seen in modern humans for all comparisons relative to size, but appears to differ from the typical human brachial index due to a slightly shorter humerus and/or slightly longer ulna. It has short metacarpals like humans only among hominoids. Thus, while Pan may have elongated its metacarpus relative to ulnar length, A. afarensis may have reduced the length of its metacarpals and possibly its humerus relative to body size from the primitive condition. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
Elitism in psychoanalysis in the USA: narcissistic defense against cumulative traumas of prejudice and exclusion
Authors: Ponder Joann
Published: December 2006

Psychoanalysts in the USA have been perceived as élitist and exclusionary. It is hypothesized that this behavior services as a narcissistic defense against feelings of marginalization and inadequacy, stemming from experiences of prejudice, loss, and exclusion in the past. It is further hypothesized that there has been an institutional and multigenerational transmission of cumulative traumas that originated with Freud and the European psychoanalysts. The roots and history of the narcissistic defense are examined, as well as its manifestations in American training and practice today. Copyright © 2006 John Wiley & Sons, Ltd.
A streetcar named desire and tennessee Williams' object‐relational conflicts
Authors: Griffies W. Scott
Published: December 2006

Art, as a symbolic expression, often reflects intrapsychic conflicts within the artist, and many of Tennessee Williams' plays contain themes of desperate loneliness, human disconnectedness, and victimization between the powerful and the weak. Williams' genius as a playwright did not save him from painful depression that contained the above themes. He described his internal conflict as a psychic split between identifications with his aggressive, alcoholic father and his sensitive, artistic Dakin (that is, maternal) roots. Of his plays A Streetcar Named Desire is one of the most compelling. This paper examines the Blanche/Stanley victim/victimizer paradigm as the dramatization of a core conflict within Williams. Using historical data from his biographies, the author attempts to explicate the hypothesis that in Williams a “Stanley” representation was in violent conflict with a “Blanche” representation. The author proposes that this conflict significantly shaped Williams' psychic organization and became a central and oft‐repeated theme in his art and his life. Copyright © 2006 John Wiley & Sons, Ltd.
Malyngamide X: The First (7R)‐Lyngbic Acid that Connects to a New Tripeptide Backbone from the Thai Sea Hare Bursatella leachii
Authors: Suntornchashwej Suchada , Suwanborirux Khanit , Koga Kazushi , Isobe Minoru
Published: December 2006

Malyngamide X (1), the first (7R)‐lyngbic acid connected to a new tripeptide backbone, was isolated from the Thai sea hare Bursatella leachii. The gross structure of 1 was established on the basis of 1D and 2D NMR and mass spectroscopic data. Combination of the NMR spectroscopic experiments with α‐methoxy‐α‐(trifluoromethyl)phenylacetic acid esters, 2,2,2‐trifluoro‐1‐(9‐anthryl)ethanol chiral solvating agent, and molecular mechanics of 1 and the synthetic molecular fragments allowed us to determine the absolute stereochemistry of all six stereogenic centers without hydrolytic degradation of the compound. Compound 1 displayed moderate cytotoxic, antitubercular, and antimalarial properties.
Toward the Total Synthesis of Onchidin, a Cytotoxic Cyclic Depsipeptide from a Mollusc
Authors: Kobayashi Shū , Kobayashi Jun , Yazaki Ryo , Ueno Masaharu
Published: December 2006

The total synthesis of onchidin (1), a cytotoxic, C2‐symmetric cyclic decadepsipeptide from a marine mollusc, according to the published structure, is described. A novel β‐amino acid, (2S,3S)‐3‐amino‐2‐methyl‐7‐octynoic acid (AMO), was efficiently prepared in high yield with high diastereo‐ and enantioselectivity based on a catalytic asymmetric three‐component Mannich‐type reaction with a chiral zirconium catalyst. The formation of sterically unfavorable N‐methyl amide and hindered ester bonds were successfully demonstrated, and final macrocyclization was achieved at a secondary‐amide site. Completion of the synthesis of 1 suggested that a revision of the structure of the natural product is required. Two diastereomers were also synthesized as candidates for the actual structure of onchidin. Furthermore, efficient solid‐phase methods were employed for the combinatorial synthesis of other derivatives to clarify the real structure of onchidin. The solid‐phase assembly of a pentadepsipeptide containing all the building blocks was established followed by dimeric cyclization in solution.
Separation of Semiconducting Single‐Walled Carbon Nanotubes by Using a Long‐Alkyl‐Chain Benzenediazonium Compound
Authors: Toyoda Shouhei , Yamaguchi Yoshifumi , Hiwatashi Masataka , Tomonari Yasuhiko , Murakami Hiroto , Nakashima Naotoshi
Published: December 2006

We designed and synthesized 4‐dodecyloxybenzenediazonium tetrafluoroborate (1), which preferentially reacts with metallic single‐walled carbon nanotubes (SWNTs) by kinetic control. We first determined the suitable experimental conditions for the preferential reaction of 1 with individually dissolved SWNTs by monitoring the decrease in absorbance for the metallic SWNT in the range of 400–650 nm in the absorption spectrum of the SWNTs. The reacted SWNTs were thoroughly rinsed with THF to obtain THF‐insoluble SWNTs. The Raman spectrum of the THF‐insoluble SWNTs showed a strong peak near 180 cm−1, which corresponds to a semiconducting breathing band. The metallic breathing bands (≈220 cm−1) and Breit–Wingner–Fano (BWF) modes (1520 cm−1) corresponding to the metallic SWNTs were much weaker than those of the pristine SWNTs. We also confirmed that metallic peaks in the range of 400–650 nm in the absorption spectrum of THF‐insoluble SWNTs that were individually dissolved in an aqueous micelle of sodium cholate were almost nondetectable. All the results indicate that the THF‐insoluble SWNTs are semiconducting.
Multi‐input–Multi‐output Molecular Response System Based on Dynamic Redox Behavior of Hexaphenylethane‐type Electron Donors with the Tetrahydrophenanthrazepine Skeleton: Strong Chiroptical Signals through the Transmission of Point Chirality to Helicity
Authors: Suzuki Takanori , Tanaka Shoko , Kawai Hidetoshi , Fujiwara Kenshu
Published: December 2006

The title heterocyclic donors undergo reversible CC bond formation/cleavage upon electron transfer (dynamic redox behavior). The helical sense in both neutral and cationic states is interconvertible by facile ring flipping. The π‐type asymmetric center on the azepine nitrogen atom induces a significant degree of diasteromeric preference, thus endowing strong CD activity based on exciton coupling. Chiroptical properties could be modified not only by redox reactions but also by heat and protonation. The present redox pairs can serve as unprecedented three‐way‐input (e, H+, Δ) and two‐way‐output (UV/Vis, CD) response systems.
Conformational study of new amphipathic α‐helical peptide models of apoA‐I as potential atheroprotective agents
Authors: Beaufils Chrystel , Alexopoulos Charalampos , Petraki Maria P. , Tselepis Alexandros D. , Coudevylle Nicolas , Sakarellos‐Daitsiotis Maria , Sakarellos Constantinos , Cung Manh Thong
Published: December 2006

Aiming at contributing to the development of potential atheroprotective agents, we report on the concept and design of two peptide models, which mimic the amphipathic helices of apoA‐I and incorporate Met into their sequences to validate its role as oxidant scavenger: Ac‐ESK(Palm)KELSKSW10SEM13LKEK(Palm)SKS‐NH2(model 1 [W10, M13]) and Ac‐ESK(Palm)KELSKSM10SEW13LKEK(Palm)SKS‐NH2(model 2 [M10, W13]). Hydrophobic residues of both models cover about the half of the surface, while the positively and negatively charged residues constitute two separate clusters on the hydrophilic face. Palmitoyl groups were introduced into the Lys‐NϵH2groups at positions 3 and 17 to contribute to the amphipathic character of the peptides and stabilize the nonpolar face of the helix. Conformational study by the combined application of 2D‐NMR and molecular dynamics simulations, CD, FTIR, and fluorescence spectroscopy revealed that model 1 adopts helical conformation and Met is well exposed to the microenvironment. Model 2 that derives from model 1 by exchanging W10(model 1) with M10and M13(model 1) with W13also displays helical characteristics, while Met is rather shielded. Oxidation experiments indicated that model 1 exhibits a 2‐fold more potent antioxidant activity towards LDL oxidation, compared to model 2, confirming the role of Met, when is devoid of steric hindrances, as oxidant scavenger for the protection of LDL. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 362–372, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
The Nernst equation applied to oxidation–reduction reactions in myoglobin and hemoglobin. Evaluation of the parameters
Authors: Saroff Harry A.
Published: December 2006

Analyses of the binding of oxygen to monomers such as myoglobin employ the Mass Action equation. The Mass Action equation, as such, is not directly applicable for the analysis of the binding of oxygen to oligomers such as hemoglobin. When the binding of oxygen to hemoglobin is analyzed, models incorporating extensions of mass action are employed. Oxidation–reduction reactions of the heme group in myoglobin and hemoglobin involve the binding and dissociation of electrons. This reaction is described with the Nernst equation. The Nernst equation is applicable only to a monomeric species even if the number of electrons involved is greater than unity. To analyze the oxidation–reduction reaction in a molecule such as hemoglobin a model is required which incorporates extensions of the Nernst equation. This communication develops models employing the Nernst equation for oxidation–reduction reactions analogous to those employed for hemoglobin in the analysis of the oxygenation (binding of oxygen) reaction. © 2006 Wiley Periodicals, Inc. Biopolymers 85: 450–455, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Differential expression of the Wnt and Frizzled genes in Flk1+ cells derived from mouse ES cells
Authors: Kim Dae Joong , Park Chun Shik , Yoon Jeong Kyo , Song Woo Keun
Published: December 2006

Embryonic stem (ES) cells have the potential to develop into various cell lineages including hemangioblasts (Flk1+), a common progenitor for hematopoietic and vascular endothelial cells. Previous studies indicate that Flk1+ cells, a marker for hemangioblast, can be derived from ES cell and that Flk1+ can be differentiated into hematopoietic or endothelial cells depending on culture conditions. We developed an improved in vitro system to generate Flk1+‐enriched cultures from mouse ES cells and used this in vitro system to study the role of Wnt signalling in early endothelial progenitor cells. We determined the expression of the Wnt and Frizzled genes in Flk1+ cells derived from mouse ES cells. RT‐PCR analyses identified significantly higher expression of non‐canonical Wnt5a and Wnt11 genes in Flk1+ cells compared to Flk1− cells. In contrast, expression of canonical Wnt3a gene was reduced in Flk1+ cells. In addition, Frizzled2, Frizzled5 and Frizzled7 genes were also expressed at a higher level in Flk1+ cells. The differential expression of Wnt and Frizzled genes in Flk1+ cells provides a novel insight into the role of non‐canonical Wnt signalling in vascular endothelial fate determination. Copyright © 2006 John Wiley & Sons, Ltd.
Silica Nanoparticles for Fluorescence Sensing of ZnII: Exploring the Covalent Strategy
Authors: Teolato Pierluigi , Rampazzo Enrico , Arduini Maria , Mancin Fabrizio , Tecilla Paolo , Tonellato Umberto
Published: December 2006

Silica nanoparticles (about 15 nm diameters), which contain a derivative of 6‐methoxy‐8‐(p‐toluensulfonamido)‐quinoline (TSQ) as a ZnII fluorescent probe covalently linked to the silica network, were prepared and studied as ZnII fluorescent chemosensors. The systems selectively detect ZnII ions in water rich solutions with a submicromolar sensitivity: 0.13 μM concentrations of ZnII can be measured with the only interference of CuII and CdII ions. Compared with free TSQ, the nanoparticles based systems have the advantage that they can be employed in aqueous solutions without aggregation problems while at the same time, they maintain a similar ZnII affinity and sensing ability. Addition of a second, substrate insensitive, fluorophore to the particles leads to the realization of a ratiometric sensor.
The Influence of Size on Phase Morphology and Li‐Ion Mobility in Nanosized Lithiated Anatase TiO2
Authors: Wagemaker Marnix , Borghols Wouter J. H. , van Eck Ernst R. H. , Kentgens Arno P. M. , Kearley Gordon J. , Mulder Fokko M.
Published: December 2006

Sustainable energy storage in the form of Li‐ion batteries requires new and advanced materials in particular with a higher power density. Nanostructuring appears to be a promising strategy, in which the higher power density in nanosized materials is related to the dramatically shortened Li‐ion diffusion paths. However, nanosizing materials also changes intrinsic material properties, which influence both ionic and electronic conductivity. In this work neutron diffraction is used to show that in addition to these two aspects, nanostructuring changes the phase behavior and morphology. Lithiated 40‐nm TiO2 anatase crystallites become single phase, either having the Li‐poor original anatase phase, or the Li‐rich Li‐titanate phase, in contrast to microsized crystallites where these two phases coexist in equilibrium within one crystal particle. In addition, LixTiO2 compositions occur with stoichiometries that are not stable in micron‐sized crystallites, indicating enhanced solid solution behavior. Reduced conduction electron densities at the sites of the Li ions are observed by NMR spectroscopy. This is accompanied by reduced spontaneous Li‐ion mobility, suggesting a correlation between the electron density at the Li‐ion site and the Li‐ion mobility. The present results show that in the case of lithiated anatase TiO2, significant effects on phase composition, morphology, and electronic configurations are induced, as well as slower intracrystallite Li diffusion.
Thermosensitive Copolymer Networks Modify Gold Nanoparticles for Nanocomposite Entrapment
Authors: Li Dongxiang , He Qiang , Cui Yue , Wang Kewei , Zhang Xiaoming , Li Junbai
Published: December 2006

The core‐shell gold nanoparticles and copolymer of N‐isopropylacrylamide (NIPAM) and N,N′‐methylenebisacrylamide (MBAA) hybrids (Au@copolymer) were fabricated through surface‐initiated atom‐transfer radical polymerization (ATRP) on the surface of gold nanoparticles in 2‐propanol/water mixed solvents. The surface of citrate‐stabilized gold nanoparticles was first modified by a disulfide initiator for ATRP. The slight cross‐linking polymerization between NIPAM and MBAA occurred on the gold surface and resulted in the formation of core‐shell Au@copolymer nanostructures that were characterized by TEM, and FTIR and UV‐visible spectroscopy. Such synthesized Au@copolymer hybrids possess clearly thermosensitive properties and exhibit “inspire” and “expire” water behavior in response to temperature changes in aqueous solution. Because of this property, we enable to trap and encapsulate smaller nanoparticles by using the free space of the copolymer‐network scaffold anchored at the gold surface.
Femtosecond Transient Absorption and Nanosecond Time‐Resolved Resonance Raman Study of the Solvent‐Dependent Photo‐Deprotection Reaction of Benzoin Diethyl Phosphate
Authors: Ma Chensheng , Du Yong , Kwok Wai Ming , Phillips David Lee
Published: December 2006

A combined femtosecond transient absorption (fs‐TA) and nanosecond time‐resolved resonance Raman (ns‐TR3) study was performed to directly detect the dynamics and elucidate the mechanism of the excited state deactivation and solvent‐dependent photo‐deprotection pathways for benzoin diethyl phosphate (BDP) in neat acetonitrile (MeCN) and 75 % H2O/25 % MeCN. Comparison of the TA spectral evolution observed in the two solvents provides explicit evidence that the photophysical deactivation of the BDP singlet excited state has little solvent dependence. The TA spectra also indicate the related internal conversion (IC) and intersystem crossing (ISC) processes occur rapidly on hundreds of femtoseconds and ∼2–3 ps time scales, respectively. From this and in conjunction with a photochemistry study and ground state resonance Raman (RR) measurements, the TA results reveal that the phenacyl localized BDP triplet state (that is mainly nπ* nature) is the common and immediate precursor to the photo‐deprotection reaction in both solvents. However, the triplet deprotection follows different pathways in neat MeCN versus the largely water containing solvent. The deprotection reaction in MeCN was determined to occur with a ∼11 ns time constant and the reaction was found to be an unimolecular process leading to elimination of the diethyl phosphoric acid apparently concurrent with cyclization to yield the benzofuran product. In the water mixed solvent, the triplet reaction was observed to proceed with a ∼15 ns time constant and the reaction leads to not only the deprotection–cyclization but also a heterolytic dissociation to release the diethyl phosphate anion through a branching and competing mechanism. The ns‐TR3spectra combined with relevant DFT calculations have been used to characterize the dynamics, structure and vibrational frequencies to help identify the important intermediates as well as to explore the reaction pathway leading to formation of the solvolysis product in the largely water solvent. A consecutive mechanism has been revealed for the heterolysis–solvolysis reaction in the water mixed solvent. The present work provides direct and irrevocable evidence for the dynamics and mechanistic description of the overall photophysics and deprotection related photochemistry for BDP.
The Formation of Byproducts in the Autoxidation of Cyclohexane
Authors: Hermans Ive , Jacobs Pierre , Peeters Jozef
Published: December 2006

In this work, a complementary experimental and theoretical approach is used to unravel the formation of byproducts in the autoxidation of cyclohexane. The widely accepted vision that cyclohexanone would be the most important precursor of undesired products was found inconsistent with several experimental observations. However, the propagation reaction of cyclohexyl hydroperoxide, which we recently put forward as the missing source of cyclohexanol and cyclohexanone, is now unambiguously identified also as the dominant path leading to byproducts. Indeed, this overlooked reaction produces large amounts of cyclohexoxy radicals, able to ring‐open via a β‐CC cleavage to ω‐formyl radicals. The pathway by which these radicals are converted into the observed and quantified byproducts is derived in this work. In this liquid‐phase reaction, solvent cages were found very important, steering the fate of nascent species.
Two‐Component Supramolecular Helical Architectures: Creation of Tunable Dissymmetric Cavities for the Inclusion and Chiral Recognition of the Third Components
Authors: Kodama Koichi , Kobayashi Yuka , Saigo Kazuhiko
Published: December 2006

The inclusion and chiral recognition of racemic arylalkanols by supramolecular helical architectures consisting of enantiopure primary amines and achiral carboxylic acids were thoroughly studied. Among the architectures examined, a supramolecular helical architecture composed of the salt of enantiopure erythro‐2‐amino‐1,2‐diphenylethanol (1 b) and benzoic acid (2 a) was found to include a wide variety of racemic arylalkanols with recognition of their chirality. The helical architecture gave a dissymmetric 1D groove in the salt crystal, and the arylalkanols were enantioselectively included in the groove. The size and shape of the groove were tunable by proper selection of the achiral carboxylic acid component. The origin of the chiral recognition with the combination 1 b/2 a is discussed on the basis of X‐ray crystallographic analyses.
Synthesis, Manipulation and Conductivity of Supramolecular Polymer Nanowires
Authors: Dong Liqin , Hollis Tom , Fishwick Steven , Connolly Bernard A. , Wright Nicholas G. , Horrocks Benjamin R. , Houlton Andrew
Published: December 2006

The synthesis of supramolecular conducting nanowires can be achieved by using DNA and pyrrole. Oxidation of pyrrole in DNA‐containing solutions yields a material that contains both the cationic polypyrrole (PPy) and the anionic DNA polymers. Intimate interaction of the two polymer chains in the self‐assembled nanowires is indicated by FTIR spectroscopy. AFM imaging shows individual nanowires to be continuous, ≈5 nm high and conformationally flexible. This feature allows them to be aligned by molecular combing in a similar manner to bare DNA and provides a convenient method for fabricating a simple electrical device by stretching DNA/PPy strands across an electrode gap. Current–voltage measurements confirm that the nanowires are conducting, with values typical for a polypyrrole‐based material. In contrast to polymerisation of pyrrole on a DNA template in bulk solution, attempts to form similar wires by polymerisation at surface‐immobilised DNA do not give a continuous coverage; instead, a beads‐on‐a‐string appearance is observed suggesting that immobilisation inhibits the assembly process.