412,602 research outputs found
Uner Tan Syndrome: History, Clinical Evaluations, Genetics, and the\ud Dynamics of Human Quadrupedalism
No full textAbstract: This review includes for the first time a dynamical systems analysis of human quadrupedalism in Uner Tan syndrome, which is characterized by habitual quadrupedalism, impaired intelligence, and rudimentary speech. The first family was discovered in a small village near Iskenderun, and families were later found in Adana and two other small villages near Gaziantep and Canakkale. In all the affected individuals dynamic balance was impaired during upright walking,and they habitually preferred walking on all four extremities. MRI scans showed inferior cerebellovermian hypoplasia with slightly simplified cerebral gyri in three of the families, but appeared normal in the fourth. PET scans showed a decreased glucose metabolic activity in the cerebellum, vermis and, to a lesser extent the cerebral cortex, except for one patient,\ud
whose MRI scan also appeared to be normal. All four families had consanguineous marriages in their pedigrees,\ud
suggesting autosomal recessive transmission. The syndrome was genetically heterogeneous. Since the initial discoveries\ud
more cases have been found, and these exhibit facultative quadrupedal locomotion, and in one case, late childhood onset. It has been suggested that the human quadrupedalism may, at least, be a phenotypic example of reverse evolution. From the viewpoint of dynamic systems theory, it was concluded there may not be a single factor that predetermines human quadrupedalism in Uner Tan syndrome, but that it may involve self-organization, brain plasticity, and rewiring, from the many decentralized and local interactions among neuronal, genetic, and environmental subsystems
Two New Cases of Uner Tan Syndrome: One Man\ud with Transition from Quadrupedalism to Bipedalism;\ud One Man with Consistent Quadrupedalism
No full textBackground: Uner Tan syndrome, first described in\ud
2005, consists of three main symptoms: habitual\ud
locomotion on all four extremities, impaired\ud
intelligence, and dysarthric or no speech. This\ud
extremely rare syndrome shows an autosomal\ud
recessive inheritance due to consanguineous\ud
marriages between parents. In general, there is a\ud
cerebellovermial hypoplasia with a mild gyral\ud
simplification in the cerebral cortex. Truncal ataxia is\ud
the main neurological finding, causing difficulty in\ud
standing and upright walking on two legs.\ud
Methods: As soon as the new cases came to light, the\ud
family was visited. After taking the basic information\ud
about the family members, the traditional neurological\ud
examinations were performed, MRI scans of the\ud
patients and of a healthy family member were taken in\ud
a hospital nearest to the residence (a small village\ud
near Kars, Turkey). The patients were also filmed to\ud
analyze their walking patterns.\ud
Results: Two individuals (case 1, 44y; case 2, 43y)\ud
among six siblings from a family with consanguineous\ud
parents exhibited Uner Tan syndrome, with\ud
quadrupedalism, impaired intelligence, and dysarthric\ud
speech. Their pedigree suggested an autosomal\ud
recessive inheritance. MRI scans showed inferior\ud
cerebellovermial and pontobulbar hypoplasia.\ud
Case 1 did not display hypotonia, while case 2 had\ud
been hypotonic for two years after birth. Case 2’s\ud
hypotonia progressively disappeared, and at three\ud
years old he started to sit, and could walk on all fours\ud
by the age of four. Case 1 was quadrupedal for 20\ud
years, and then walked upright with the aid of a\ud
walking stick. Tendon reflexes were normal in case 1\ud
but hyperactive in the lower extremities of case 2;\ud
Babinsky was absent in case 1 but bilaterally present\ud
in case 2. There was no nystagmus, no strabismus,\ud
and no pes pedus in either case. Cognition was\ud
severely impaired in both.\ud
Conclusion: The emergence of quadrupedalism\ud
during development, with a transition into bipedalism\ud
in case 1, and the emergence of the quadrupedalism\ud
after a full hypotonia and no locomotion in case 2,\ud
were considered as examples of the processes of\ud
adaptive self-organization, from the viewpoint of\ud
dynamic systems theory
Alloteratura Tan & Gorochov & Wahab 2017, s. str.
No full textSubgenus Alloteratura s. str. Diagnosis (from Tan & Artchawakom, 2017). Genicular lobe of hind femur rounded without distinct spinule. Male subanal plate partly or completely sclerotized; and articulated or fused with posteroventral corners of last tergite (Gorochov, 2016).Published as part of Tan, Ming Kai, Gorochov, Andrej V. & Wahab, Rodzay Bin Haji Abdul, 2017, New taxa and notes of katydids from the tribe Meconematini (Orthoptera: Meconematinae) from Brunei Darussalam in Zootaxa 4337 (3), DOI: 10.11646/zootaxa.4337.3.4, http://zenodo.org/record/102495
Additions to the moss flora of Endau Rompin National Park, Johore State, peninsular Malaysia
No full textIn a recent survey of the Endau Rompin National Park (ERNP) in Johore State, 81 species and 4 varieties of mosses were documented. This increases the previous count from 62 species and 3 varieties of mosses in ERNP to 111 species and 5 varieties in total. Of these, 30 species are new records for Johore State. Rhaphidostichum bunodicarpum and Trichosteleum stigmosum are two species new to Peninsular Malaysia. Thuidium assimile is a new record for West Malesia. A new combination, Papillidiopsis aquaticum (Dix.) Boon-Chuan Ho & B.C. Tan is proposed. In terms of species composition, the pan-tropical families of Calymperaceae, Fissidentaceae, Leucobryaceae and Sematophyllaceae predominate the moss flora of ERNP
Alloteratura Tan & Gorochov & Wahab 2017, s. str.
No full textSubgenus <i>Alloteratura</i> s. str. <p> <b>Diagnosis (from Tan & Artchawakom, 2017).</b> Genicular lobe of hind femur rounded without distinct spinule. Male subanal plate partly or completely sclerotized; and articulated or fused with posteroventral corners of last tergite (Gorochov, 2016).</p>Published as part of <i>Tan, Ming Kai, Gorochov, Andrej V. & Wahab, Rodzay Bin Haji Abdul, 2017, New taxa and notes of katydids from the tribe Meconematini (Orthoptera: Meconematinae) from Brunei Darussalam in Zootaxa 4337 (3)</i>, DOI: 10.11646/zootaxa.4337.3.4, <a href="http://zenodo.org/record/1024958">http://zenodo.org/record/1024958</a>
Total synthesis of TAN-1057 and analogues
No full text1997 Spring.Includes bibliographical references.Part I. An asymmetric and stereochemically unambiguous construction of diaminopimelic acid and related system using the chiral, non-racemic diphenyl oxazinones glycinate templates has been developed. The preparations of (R,R)-DAP, (S,S)-DAP, (S,S)-2,7-diaminosuberic acid, and mono-N-protected (S,R)-DAP are described. The synthesis of γ-D(L)-glutamyl-L-meso-diaminopimelic acid dipeptide, a subunit of both FK-156 and FK-565, is also described. The availability of both optical antipodes of the glycinate templates renders this chemistry adaptable to prepare all possible diastereoisomers of substances based on the DAP skeleton in optically pure form.Part II. The first total synthesis of anti-MRSA dipeptides TAN-1057 A~D has been achieved. A new efficient method for preparation of amidinoureas has been developed and successfully applied to the total synthesis of TAN-1057. More importantly, this concise total synthesis paves the way for access to analogues that are not available from natural sources. Eight new analogues of TAN-1057 were designed, synthesized and assayed against MRSA. A new synthetic analogue 102 (CY-1800) showed very similar activity to that of TAN-1057. Other analogues prepared showed weak or no activity against Staphylococcus aureus up to 1 mg/mL. The success on discovery of a new potent anti-MRSA analogue proved the usefulness of this highly flexible strategy for the development of better analogues than the natural ones for the potential use as antibiotics
Üner Tan Syndrome: Review and Emergence of Human Quadrupedalism in Self-Organization,\ud Attractors and Evolutionary Perspectives\ud
No full textThe first man reported in the world literature exhibiting habitual quadrupedal locomotion was discovered by a British traveler and writer on the famous Baghdat road near Havsa/Samsun on the middle Black-Sea coast of Turkey (Childs, 1917). Interestingly, no single case with human quadrupedalism was reported in the scientific literature after Child's first description in 1917 until the first report on the Uner Tan syndrome (UTS: quadrupedalism, mental retardation, and impaired speech or no speech)in 2005 (Tan, 2005, 2006). Between 2005 and 2010, 10 families exhibiting the syndrome were discovered in Turkey with 33 cases: 14 women (42.4%) and 19 men (57.6%). Including a few cases from other countries, there were 25 men (64.1%)and 14 women (35.9%). The number of men significantly exceeded the number of women (p < .05). Genetics alone did not seem to be informative for the origins of many syndromes, including the Uner Tan syndrome. From the viewpoint of dynamical systems theory, there may not be a single factor including the neural and/or genetic codes that predetermines the emergence of the human quadrupedalism.Rather, it may involve a self-organization process, consisting of many decentralized and local interactions among neuronal, genetic, and environmental subsystems. The most remarkable characteristic of the UTS, the diagonal-sequence quadrupedalism is well developed in primates. The evolutionarily advantage of this gait is not known. However, there seems to be an evolutionarily advantage of this type of locomotion for primate evolution, with regard to the emergence of complex neural circuits with related highly complex structures. Namely, only primates with diagonal-sequence quadrupedal locomotion followed an evolution favoring larger brains, highly developed cognitive abilities with hand skills, and language, with erect posture and bipedal locomotion, creating the unity of human being. It was suggested that UTS may be considered a further example for Darwinian diseases, which may be associated with an evolutionary understanding of the disorders using evolutionary principles, such as the natural selection. On the other hand, the human quadrupedalism was proposed to be a phenotypic example of evolution of reverse, i.e., the reacquisition by derived populations of the same character states as those of ancestor populations. It was also suggested that the emergence of the human quadrupedalism may be related to self-organizing processes occurring in complex systems, which select or attract one preferred behavioral state or locomotor trait out of many possible attractor states. Concerning the locomotor patterns, the dynamical systems in brain and body of the developing child may prefer some kind of locomotion, according to interactions of the internal components and the environmental conditions, without a direct role of any causative factor(s), such as genetic or neural codes, consistent with the concept of self-organization, suggesting no single element may have a causal priority
Pseudoteratura Tan & Gorochov & Wahab 2017, s. str.
No full textSubgenus Pseudoteratura s. str. Diagnosis. This subgenus differs from the subgenus Subtilotura in the male epiproct larger and specialised (i.e. with lobules and projections; in Subtilotura, this epiproct is small and more or less rounded, tenth abdominal tergite in male with more or less deep posteromedian notch (instead very shallow notch), and male genitalia with 1 or 2 large dorsal sclerotized lobes (instead three such lobes) (Gorochov, 2008).Published as part of Tan, Ming Kai, Gorochov, Andrej V. & Wahab, Rodzay Bin Haji Abdul, 2017, New taxa and notes of katydids from the tribe Meconematini (Orthoptera: Meconematinae) from Brunei Darussalam in Zootaxa 4337 (3), DOI: 10.11646/zootaxa.4337.3.4, http://zenodo.org/record/102495
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