Catching a natural killer in the act

Small pictures of disease fighting cells may be help treat immune deficiency disorders. Jordan Orange of the Children’s Hospital of Philadelphia and colleagues used a superpowerful new microscope to watch how immune cells called natural killer cells feed a poison pill called a lytic granule to tumors or virus-infected cells. Scientists used to think a big hole in the middle of a dense mesh of spaghetti-like molecules called F-actin let granules stream out of the natural killer cell. A new study, shows that the meshwork parts just enough to let single lytic granules pass, with F-actin helping squeeze the granule through. People with immune deficiency disorders may have defects that prevent lytic granules from exiting the natural killer cell.

Non metals

The non-metals or non-metallic elements; hydrogen (H), carbon (C), nitrogen (N), oxygen (O), phosphorus (P), sulphur (sulfer) (S), selenium (Se), (Uuo may belong here) and the noble gases form a relatively small group with a step like pattern towards the left-hand side of the periodic table (hydrogen being the odd one out on the right of the table). Non-metals are not strictly defined, but tend to show characteristic properties like poor heat and electrical conductivity, form acidic oxides, dull low lustre and brittle, low densities, low melting points and high electro negativity.
Hydrogen can become metallic when exposed to extremely high pressures. Some allotropes of elements show more pronounced metal, metalloid or non-metal behaviour than others. The element carbon; its diamond allotrope is non-metallic, however the graphite allotrope is electrically conductive showing characteristic more like a metalloid. Phosphorus, and selenium also have allotropes which display borderline behaviour.
Point at or click an element for more information:

Group*** Period

1 IA 1A

2 IIA 2A

3 IIIB 3B

4 IVB 4B

5 VB 5B

6 VIB 6B

7 VIIB 7B

8 VIII 8

9 VIII 8

10 VIII 8

11 IB 1B

12 IIB 2B

13 IIIA 3A

14 IVA 4A

15 VA 5A

16 VIA 6A

17 VIIA 7A

18 VIIIA 8A

1

1 H 1.008

2 He4.003

2

3 Li6.941

4 Be 9.012

5 B10.81

6 C12.01

7 N 14.01

8 O16.00

9 F19.00

10 Ne20.18

3

11 Na 22.99

12 Mg 24.31

13 Al26.98

14 Si28.09

15 P 30.97

16 S32.07

17 Cl35.45

18 Ar39.95

4

19 K 39.10

20 Ca40.08

21 Sc44.96

22 Ti47.88

23 V50.94

24 Cr52.00

25 Mn54.94

26 Fe55.85

27 Co58.47

28 Ni58.69

29 Cu63.55

30 Zn65.39

31 Ga69.72

32 Ge72.59

33 As 74.92

34 Se78.96

35 Br79.90

36 Kr83.80

5

37 Rb85.47

38 Sr87.62

39 Y 88.91

40 Zr91.22

41 Nb92.91

42 Mo95.94

43 Tc(98)

44 Ru101.1

45 Rh102.9

46 Pd106.4

47 Ag107.9

48 Cd112.4

49 In114.8

50 Sn118.7

51 Sb 121.8

52 Te127.6

53 I126.9

54 Xe131.3

6

55 Cs132.9

56 Ba137.3

*

72 Hf178.5

73 Ta180.9

74 W183.9

75 Re186.2

76 Os190.2

77 Ir190.2

78 Pt195.1

79 Au197.0

80 Hg200.5

81 Tl204.4

82 Pb207.2

83 Bi209.0

84 Po(209)

85 At(210)

86 Rn(222)

7

87 Fr(223)

88 Ra(226)

**

104 Rf(261)

105 Db(262)

106 Sg(266)

107 Bh(264)

108 Hs(269)

109 Mt(268)

110 Ds(281)

111 Rg(272)

112 Uub(285)

113 Uut(284)

114 Uuq (289)

115 Uup(288)

116 Uuh(292)

117 Uus()

118 Uuo(294)

Lanthanide Series* (Lanthanoid)

57 La138.9

58 Ce140.1

59 Pr 140.9

60 Nd144.2

61 Pm(145)

62 Sm150.4

63 Eu152.0

64 Gd157.3

65 Tb158.9

66 Dy162.5

67 Ho164.9

68 Er167.3

69 Tm168.9

70 Yb173.0

71 Lu175.0

Actinide Series** (Actinoids)

89 Ac(227)

90 Th232.0

91 Pa(231)

92 U(238)

93 Np(237)

94 Pu(244)

95 Am(243)

96 Cm(247)

97 Bk(247)

98 Cf(251)

99 Es(252)

100 Fm(257)

101 Md(258)

102 No(259)

103 Lr(262)

***Groups are by 3 notation conventions.

Scientific Summer

This summer I was in the water 24/7. I swam in pools mostly, but also in lakes. I also went mountain biking and rode on a zip line. I hiked and camped in the woods. During our move from the United States I packed up and move a lot of boxes. And I also travelled on an airplane.



Many of the things I did this summer involved science. Swimming involves Newton’s third law of motion which states that “to every force there is an opposite but equal attraction.” So when you kick your legs or pull your arms you are applying a slightly down-word force on the water, and then apply a force to the water behind you. This is a "reaction force”  made by the water onto a body, such that the water pushes the body up and "forward" in the water, allowing you to move through in the water.



For mountain biking you need a special bike with flat tires to help you get over rocks, water, and roots. Less pressure in the tires allows the rider to be more balanced and acts as a shock absorber of the energy.



Airplanes are programmed to work the same way birds fly. The physical force that propels the aircraft from take-off to flight. Anything, from jet engines to other propulsion devices, are the main source of this applied energy. The pulling of the propeller powered engine is another form of thrust used in aircraft. Thrust is used to overcome weight and drag, the two major opposing forces that cause most resistance to flight.



My summer was full of science.  I just needed to think about how many of my activities were related.

grade 8

hi