Autistic spectrum disorder in prehistory

Individuals with 'extraordinary' or 'different' minds have been suggested to be central to invention and the spread of new ideas in prehistory, shaping modern human behaviour and conferring an evolutionary advantage at population level. In this article the potential for neuropsychiatric conditions such as autistic spectrum disorders to provide this difference is explored, and the ability of the archaeological record to provide evidence of human behaviour is discussed. Specific reference is made to recent advances in the genetics of these conditions, which suggest that neuro psychiatric disorders represent a non-advantageous, pathological extreme of the human mind and are likely a by-product rather than a cause of human cognitive evolution

Thermodynamically stable lithium silicides and germanides from density-functional theory calculations

Density-functional-theory (DFT) calculations have been performed on the Li-Si and Li-Ge systems. Lithiated Si and Ge, including their metastable phases, play an important technological r\^ole as Li-ion battery (LIB) anodes. The calculations comprise structural optimisations on crystal structures obtained by swapping atomic species to Li-Si and Li-Ge from the X-Y structures in the International Crystal Structure Database, where X={Li,Na,K,Rb,Cs} and Y={Si,Ge,Sn,Pb}. To complement this at various Li-Si and Li-Ge stoichiometries, ab initio random structure searching (AIRSS) was also performed. Between the ground-state stoichiometries, including the recently found Li$_{17}$Si$_{4}$ phase, the average voltages were calculated, indicating that germanium may be a safer alternative to silicon anodes in LIB, due to its higher lithium insertion voltage. Calculations predict high-density Li$_1$Si$_1$ and Li$_1$Ge$_1$ $P4/mmm$ layered phases which become the ground state above 2.5 and 5 GPa respectively and reveal silicon and germanium's propensity to form dumbbells in the Li$_x$Si, $x=2.33-3.25$ stoichiometry range. DFT predicts the stability of the Li$_{11}$Ge$_6$ $Cmmm$, Li$_{12}$Ge$_7$ $Pnma$ and Li$_7$Ge$_3$ $P32_12$ phases and several new Li-Ge compounds, with stoichiometries Li$_5$Ge$_2$, Li$_{13}$Ge$_5$, Li$_8$Ge$_3$ and Li$_{13}$Ge$_4$.Comment: 10 pages, 5 figure

Radiocarbon and stable isotope evidence of dietary change from the Mesolithic to the Middle Ages in the iron gates: New results from Lepenski Vir

A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the delta(15)N values as an indicator of the percentage of freshwater protein in the human diet, the C-14 data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired C-14 and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BR The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier delta(15)N signals and slightly heavier delta(13)C, while individuals of Early Neolithic and Chalcolithic age have lighter delta(15)N and delta(13)C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with "Final Mesolithic" C-14 ages show delta(15)N and delta(13)C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain

A First Principles Theory of Nuclear Magnetic Resonance J-Coupling in solid-state systems

A method to calculate NMR J-coupling constants from first principles in extended systems is presented. It is based on density functional theory and is formulated within a planewave-pseudopotential framework. The all-electron properties are recovered using the projector augmented wave approach. The method is validated by comparison with existing quantum chemical calculations of solution-state systems and with experimental data. The approach has been applied to verify measured J-coupling in a silicophosphate structure, Si5O(PO4)6Comment: 9 page

Letter from J[oseph] C. Pickard to John Muir, 1902 Jan 7.

JOSEPH C. PICKARD,MAYWOOD, ILL.January 7th. 1902.My Dear Mr. Muir,I think you will enjoy the enclosed letter. - Mrs. Tydale is now the wife of a Boston lawyer. For some years before marriage she was Professor of English Literature in the University of Iowa of which my brother was President. Wh[illegible] visiting her last summer our talk drifted to yourself. She had not read your Mountains of California - on my return to Boston I sent her a copy, & this letter is her acknowledgement. You need not trouble to return it, as I have made a copy. I trust Christmas and New Year\u27s brought you holiday blessings. The good abide with you.Cordially yoursJ C. Pickard0292

Letter from J[oseph] C. Pickard to John Muir, 1909 Sep 2.

[1]Maywood Ills. 2 Sept. 1909Dr. John MuirMartinez, CaliforniaMy dear Friend.I have read with great pleasure your Stickeen . I find the same pen finds alike in narration & description, and the same genial soul that loveth All things both great and small. I can but recall the day you came to me with wooden clocks & asked a place for them. Wonder-working clocks regulating so much of labor as student & teacher! I trust you have them still in place of honor.A few years ago I was in Edinburg I went into the cemetery at foot of Calton Hill, to see the bronze figure of L[illegible] & the tomb of Hume. I found near those a monument to 3 (or 4) martyrs (banished for love of their fellowman. I copied inscriptions remarks made at their trial. One read as follows: I have devoted myself to the04573 [2]cause of the people. It is a good cause. It shall ultimately prevail. It shall ultimately triumph . Thomas Muir in Court of Judiciary. Aug. 20. 1793. - The cause did ultimately triumph & the people erected the monument. You must know the spot & its memory, as I believe your early life was not far away.- I have thought you must of that noble stock, for in you is somewhat of that heroic grandeurI wish you might meet my brother J. L. who lives in Cupertino (85 years of age) & his grandson in San Francisco, Perhaps you remember Henry Butler & my son Charles as boys about the university. Henry is a lawyer in Superior, & Charles a lawyer in Chicago. Charles spent a week or two this summer with his invalid wife in the Yosemite. I hoped he would find you. Both boys are successful in their profession.Very cordially yoursJ. C. Pickard[3]PS. Ninety years ago my wife\u27s grandfather James St[illegible] & his son published \u27Illustrations of Edinburg with a history of the city. One of the engravings is of the old Tol. booth. I found a copy in a second hand book store, & brought it away with me paying $2.25 for it. A rare work now. MR. St[illegible] was a distinguished delineator & engraver in London.- In the description of Hume\u27s monument is given a suggested epitaph, which you may not have seen. I copy it. Within this circular idea, vulgarly called a tomb- Rest the impressions & ideas That constituted Hume. I quote from memory.JCP0457

Letter from J[oseph] C. Pickard to John Muir, 1901 Dec 1.

[letterhead]December 1st. 1901My Dear Mr. Muir,Returning from a long Sojourn in New England, among native s[cenes?]. With brothers & sisters, I find a copy of the Atlantic Monthly - kindly sent by you. I have read you contribution to that number with the interest which attaches to all others that I see. Thanks for your thoughtful kindness. I wish I could pay in kind , but I have written little that you would care to read. I take pleasure however, in extending knowledge of yourself & of your published book on the Mountains of California among my friends in Maine & Massachusetts from Portland to Cape Cod.With heartiest good will,Your friendJ.C. Pickard0282

Energetics of hydrogen/lithium complexes in silicon analyzed using the Maxwell construction

We have studied hydrogen/lithium complexes in crystalline silicon using density-functional-theory methods and the ab initio random structure searching (AIRSS) method for predicting structures. A method based on the Maxwell construction and convex hull diagrams is introduced which gives a graphical representation of the relative stabilities of point defects in a crystal and enables visualization of the changes in stability when the chemical potentials are altered. We have used this approach to study lithium and hydrogen impurities in silicon, which models aspects of the anode material in the recently-suggested lithium-ion batteries. We show that hydrogen may play a role in these anodes, finding that hydrogen atoms bind to three-atom lithium clusters in silicon, forming stable {H,3Li} and {2H,3Li} complexes, while the {H,2Li} complex is almost stable.Comment: (5 pages, 4 figures

Lithiation of silicon via lithium Zintl-defect complexes

An extensive search for low-energy lithium defects in crystalline silicon using density-functional-theory methods and the ab initio random structure searching (AIRSS) method shows that the four-lithium-atom substitutional point defect is exceptionally stable. This defect consists of four lithium atoms with strong ionic bonds to the four under-coordinated atoms of a silicon vacancy defect, similar to the bonding of metal ions in Zintl phases. This complex is stable over a range of silicon environments, indicating that it may aid amorphization of crystalline silicon and form upon delithiation of the silicon anode of a Li-ion rechargeable battery.Comment: 4 pages, 3 figure

Cognitive and psychological sequelae of hydrocephalus and spina bifida: turning interesting theoretical research into useful clinical intervention and guidelines

Background Ventricular shunts have significantly improved the prognosis of people with hydrocephalus and spina bifida; nevertheless, there are lifelong effects, which in many cases is associated with a cognitive profile of short term memory, attention and executive function difficulties (Iddon et al, 1996, 2001, 2003, 2004). There can also be psychological sequelae including depression and low self-esteem. The aim of this study is to develop clinical practice guidelines to inform intervention strategies to help patients and their carer to manage these difficulties. Materials and methods A three-stage project is being developed. Stage 1: A survey will be carried out to ascertain the needs of the client group, including gaps in local service provision and the impact of cognitive and psychological difficulties on everyday lives. Stage 2: Using data previously collected as well as new data, a detailed review will take place of specific cognitive difficulties and how these relate to everyday functions. Stage 3: A cognitive training programme will be developed as a guideline for practical clinical intervention. Results Data will be presented, showing the unmet need of people with hydrocephalus and spina bifida (N = 150, range of IQ's). Preliminary results of the new project will be presented and discussed. Conclusion It is not possible to provide a complete psychological support for individuals with hydrocephalus attending one London hospital clinic for their annual multi-disciplinary review. However, this project aims to bridge the theoretical/clinical gap we have previously identified in order to inform and guide their local services of the unmet needs of these clients, and to recommend appropriate interventions. This we anticipate will improve patients' quality of life